1. S4 Credit Wages & Salaries Wages Rises Money www.mathsrevision.com Time-Sheets Overtime Pay Piecework & Commission Payslip National Insurance Income Tax Banks & Building Societies Savings and Interest Compound Interest Appreciation & Depreciation Working Backwards

2. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Factorise Q2.Write down the probability of picking out a number greater than 7 in the national lottery. Q3.If a = -2 and b = -1 calculate Q4.Calculate 4a 2 – 3b 2 www.mathsrevision.com

3. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.Understand the term weekly monthly and annual salary. 1.To explain how to work out weekly, monthly and annual salary / wage. 2.Calculate weekly, monthly and annual salary. www.mathsrevision.com Wages & Salaries

4. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Annual Wage / Salary How much a person is paid in a year www.mathsrevision.com Wages & Salaries 12 months in a year 52 weeks in a year

5. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. £12 428 ÷ 52 = £ 239 Weekly wage = www.mathsrevision.com Example 1 : A shop assistant gets paid £12 428 a year. How much is her weekly wage. Wages & Salaries

6. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. £1 100 x 12 = £ 13 200Annual Salary = www.mathsrevision.com Example 2 : A mechanic gets paid £1 100 a month. A bus driver gets paid £260 a week. Who gets the better annual salary. Wages & Salaries Mechanic : Bus Driver : £260 x 52 = £ 13 520Annual Salary = Bus driver has better annual wage

7. S4 Credit £10.50 x 40 = £420Weekly Pay is = www.mathsrevision.com Example 3 : Jim is a joiner his hourly rate of pay is £10.50. He works 40 hours a week. What is his basic weekly pay? What is his annual salary? Wages & Salaries £420 x 52 = £21 840Annual Salary =

8. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Example 4 : Daryl gets an annual salary of £ 30 000. What is his monthly wage. What is his weekly wage. Wages & Salaries £30 000 ÷ 12 = £ 2 500 Monthly wage: Weekly wage : £30 000 ÷ 52 = £ 576.92

9. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 3.1 Ch 2 (page 27) Odd questions www.mathsrevision.com Wages & Salaries

10. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Find the roots for the quadratic to 1 decimal place Q2.Write down the probability of picking out a number greater than 20 in the national lottery. Q3.If a = -3 then find f(a) Q4.Does f(a) = 2a 3 www.mathsrevision.com

11. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.To explain how to work out new wages after a wage rise. 1.Calculate a percentage rise. www.mathsrevision.com Wages Rises 2.Calculate new wages after a percentage rise.

12. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Example 1 : Gerry earned an annual salary of £ 18 000 last year. He receives a 4% rise this year. What is his new salary. 4 ÷ 100 x £18 000 = £ 720 Rise : New salary : £18 000 + £720 = £ 18 720 Wages Rises

13. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Example 2 : Amanda new weekly wage after a 5% pay rise, is £363.93 Calculate her wage before the rise. 100% + 5% = 105% 105% = 363.93 100% = 363.93 ÷ 105 x 100 = £346.60 Wages Rises

14. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 3.2 Ch 2 (page 28) Odd questions www.mathsrevision.com Wages Rises

15. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Find the roots of the quadratic to 1 decimal place Q2.Write down the probability of picking out a number greater than 33 in the national lottery. Q3.If f(x) = (x + 1)(x - 2) find f(-1) Q4.Explain why the line y + 3x - 6 = 0 cut the x-axis at (2,0). www.mathsrevision.com

16. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.To work out hours worked from a time sheet using the counting method. 1.Calculate hours worked. www.mathsrevision.com Timesheet

17. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Timesheet Name : Joe BloggsEmployee No. 12345 Week10 InOutInOutTotal hours worked Mon08001200130017008 Tue08001200133017308 Wed08301230130016307.5 Thurs08001300140017008 Fri08001230140016307 Total38.5

18. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Example 1 : Frances starts work at 7.30am and finishes at 3pm. How many hours did she work. 8.00am7.30am3pm Total 30mins + 7hours = 7hours 30 mins 30mins 7 hours Timesheet

19. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. www.mathsrevision.com Example2 : Rachel hourly rate is £6.50. How much is her weekly wage. Weekly wage = 38.5 x 6.50 = £ 250.25 Timesheet

20. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 4.1 Ch 2 (page 30) Odd questions www.mathsrevision.com Timesheet

21. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Solve the equation to 1 decimal place Q2.Write down the probability of picking out a number greater than 49 in the national lottery. Q3.Factorise Q4.Where does the line 2y -6x + 8 =0 cut y-axis. 9m 2 – 25n 2 www.mathsrevision.com

22. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.To explain how to work out wages which include overtime rates. 1.Understand the terms overtime, ‘double time’ and ‘time and a half’. www.mathsrevision.com Overtime Pay 2.Calculate wages with overtime.

23. S4 Credit Overtime :When you do extra work above your basic hours. www.mathsrevision.com You get a better hourly rate for overtime. Write down the two common rates of overtime Double time (x2) Time and a half (x1.5) Overtime Pay

24. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. 4 x £6 x 2 = £48.004 hours Overtime is = www.mathsrevision.com Example 1 : Anthony the painter works for £6.00 per hour. His overtime rate is “Double time”. What does he get paid for 4 hours overtime. Overtime Pay

25. S4 Credit 5 x £8 x 2 = £80.005 hours overtime is = www.mathsrevision.com Example 2 : John the gardener works a basic 40 hours a week. He does 5 hours overtime at ‘double time’ on Saturday. His hourly rate is £8 per hour. Work out his overtime pay and then his total pay. 40 x £8 = £320.0040 hours basic time is = Total pay is = £320 + £80 = £400 Overtime Pay

26. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 4.2 Ch 2 (page 31) Even questions www.mathsrevision.com Overtime Pay

27. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Find the roots to 1 decimal place Q2.A sofa is reduced by 20% to £300 in a sale. Is the original price £360. Q3.Calculate www.mathsrevision.com

28. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.To explain how to work out wages when commission is involved. 1.Understand the term commission. www.mathsrevision.com Commission 2.Calculate wages involving commission.

29. S4 Credit Commission :Money earned based on how much you sell. Usual expressed as a percentage. www.mathsrevision.com Write some people who get commission Car sales person Double glazing sales person Commission

30. S4 Credit www.mathsrevision.com Example 1 : Anthony does maths tuition and charges £12.50. (a) How much does he earn in a week if he does 9 lesson. (b) How much for a course of 20 lessons. 12.50 x 9 = £112.50 (a) 12.50 x 20 = £250 (b) Commission

31. S4 Credit www.mathsrevision.com Example 2 : Sean sells cars. He is paid a commission of 5% on any cars he sells. Last week he sold £ 20 000 worth of cars. How much commission was he paid ? 5 ÷ 100 x £20 000 = £ 1 000 Commission : Commission

32. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 5.1 Ch 2 (page 32) Odd questions www.mathsrevision.com Commission

33. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Find the roots to 1 decimal place Q2.A house has increase by 10% to £77 000 in a year. Find the price before the increase. Q3.Find the gradient and where the line y +4x – 3 =0 cuts the x-axis. Q4.Calculate www.mathsrevision.com

34. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.To explain how to work out NET pay. 1.Understand the terms Gross, Deductions and NET pay. www.mathsrevision.com Payslips 2.Calculate NET pay.

35. S4 Credit Gross Pay:What you are paid by the employer. www.mathsrevision.com Tax National Insurance Deductions:Taken off your wages. Net Pay:Your take home pay. Write down some Pension Payslips

36. S4 Credit www.mathsrevision.com Example 1 : Calculate the Net wage for the following :GrossDeductions Net Wage £15 550 £3 400 £13 025 £2 905 £22 430 £5 094 £12 150 £10 120 £17 336 Payslips

37. S4 Credit www.mathsrevision.com Example 2 : Calculate the Net wage for this payslip : 704.00 149.00 555.00 Payslips

38. S4 Credit www.mathsrevision.com Example 3 : Calculate the Net wage for this payslip : 739.15 207.76 531.39 Payslips

39. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 6.1 Ch 2 (page 33) www.mathsrevision.com Payslips

40. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Find the standard deviation for the data below Q2.Solve the equation www.mathsrevision.com 0 < x < 180

41. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.To explain how to work out NET pay. 1.Understand the terms Gross, Deductions and NET pay. www.mathsrevision.com 2.Calculate NET pay. National Insurance Contributions

42. S4 Credit This is a government tax on earnings intended to contribute towards.......... Do you know the rest ! www.mathsrevision.com ill-health unemployment State Pension National Insurance Contributions

43. S4 Credit www.mathsrevision.com Rates for 2004 / 05RateWeeklyAnnual0% < £91 < £4745 11% £91 - £610 £4745 - £31 720 1% > £610 > £31 720 National Insurance Contributions

44. S4 Credit www.mathsrevision.com National Insurance ContributionsRateWeeklyAnnual0% < £91 < £4745 11% £91 - £610 £4745 - £31 720 1% > £610 > £31 720 Calculate how much Kylo will pay in NIC if he earns £400 a week. He has to pay NIC on£400 - £91 = £309 11% of £309 = 11 ÷ 100 x 309 = £33.99

45. S4 Credit www.mathsrevision.com National Insurance ContributionsRateWeeklyAnnual0% < £91 < £4745 11% £91 - £610 £4745 - £31 720 1% > £610 > £31 720 Charlotte earns £1000 a week. How much NIC will she pay per week. She has to pay NIC on£610 - £91 = £519 @ 11% £1000 – £610 = £390 @ 1% (11 ÷ 100 x 519) + (1 ÷ 100 x 390) = £60.99

46. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 7.1 Ch 2 (page 35) www.mathsrevision.com National Insurance Contributions

47. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Find the standard deviation for the data below Q2.Solve the equation www.mathsrevision.com 0 < x < 360

48. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.To explain how to work out Income Tax calculations. 1.Understand the term Income Tax. www.mathsrevision.com 2.Calculate Income Tax for a given salary. Income Tax

49. S4 Credit If your income in a tax year is below a certain value you do not pay tax. The tax allowance is made up of a personal allowance plus other special allowances. www.mathsrevision.com Membership of professional bodies Special clothing equipment Income Tax

50. S4 Credit www.mathsrevision.com Taxable income Rate of Tax Up to £4745 0% £0 - £2020 10% £2020 - £31 400 22% Over £31 400 40% Income Tax Taxable Rates for 2004 / 05

51. S4 Credit www.mathsrevision.com Income Tax Calculate David’s income tax if he earns £27 000 a year. Personal allowance £4745 Taxable Income £27 000 – £4745 = £22 255 Tax @ 10% = 10% of £2020 = £202 £4653.70 Tax @ 22% = 22% of ( £22 255 - £2020) Taxable income Rate of Tax Up to £4745 0% £0 - £2020 10% £2020 - £31 400 22% Over £31 400 40% = 22% of £20 235 = £4451.70 Total Income tax = £202 + £4451.70 =

52. S4 Credit www.mathsrevision.com Income Tax Lauren, a successful business woman earns £70 000. What is her total tax paid and her income after tax. Personal allowance £4745 Taxable Income £70 000 – £4745 = £65 255 Tax @ 10% = 10% of £2020 = £202 £20 207.60 Tax @ 22% = 22% of ( £31 400 - £2020) = £6463.60 Taxable income Rate of Tax Up to £4745 0% £0 - £2020 10% £2020 - £31 400 22% Over £31 400 40% Total tax = £202 + £6463.60 + 13 542 = Tax @ 40% = 40% of ( £65 255 - £31 400) = £13 542

53. S4 Credit www.mathsrevision.com Income Tax £20 207.60 Taxable income Rate of Tax Up to £4745 0% £0 - £2020 10% £2020 - £31 400 22% Over £31 400 40% Total tax = £202 + £6463.60 + 13 542 = = £49 792.40 Income after tax = £70 000 - £20 207.60

54. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 8.1 & 8.2 Ch 2 (page 37) Even Numbers Only www.mathsrevision.com Income Tax

55. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Find the standard deviation for the data below Q2.Find the coordinates where the line and curve meet. www.mathsrevision.com

56. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.To explain how bank accounts work. 1.Understand the main services from a bank account. www.mathsrevision.com 2.Interpret bank statements. Banks & Building Societies

57. S4 Credit Banks and Building Societies help us manage our money. www.mathsrevision.com Banks & Building Societies What might we get if we open an account at a bank ? Credit Card Cash Card Cheque book DR = overdrawn

58. S4 Credit www.mathsrevision.com Banks & Building Societies Copy and complete the bank statement 61.03 33.46 DR 590.62

59. S4 Credit 2-May-15Created by Mr. Lafferty Maths Dept. Now try Ex 9.1 Ch 2 (page 40) www.mathsrevision.com Banks & Building Societies

60. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.A line passes through the points ( 3, 8) and ( 5,10) (a) Find the gradient. (b)Where does the line cross the x and y axis. www.mathsrevision.com Q2.Solve x - 2y = 10 2x + y = 20

61. S4 Credit Learning Intention Success Criteria 1.To know the meaning of the term simple interest. 1.To understand the term simple interest and compound interest. 2.To know the meaning of the term compound interest. www.mathsrevision.com Savings & Interest 3.Know the difference between simple and compound interest. Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 61

62. S4 Credit Just working out percentages www.mathsrevision.com Simple Interest I have £400 in the Bank. At the end of each year I receive 7% of £400 in interest. How much interest do I receive after 3 years. How much do I now have? Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 62 Savings & Interest

63. S4 Credit Now try Ex 10.1 Ch2 (page 41) www.mathsrevision.com Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 63 Savings & Interest

64. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Find the standard deviation for the data below Q2.Find the coordinates where the line and curve meet. www.mathsrevision.com

65. S4 Credit Learning Intention Success Criteria 1.To know when to use compound formula. 1.To show how to use the compound formula for appropriate problems. 2.Solve problems involving compound formula. www.mathsrevision.com Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 65 Compound Interest

66. S4 Credit www.mathsrevision.com Compound Interest Interest calculated on new value every year Real life Interest is not a fixed quantity year after year. One year’s interest becomes part of the next year’s amount. Each year’s interest is calculated on the amount at the start of the year. Example Daniel has £400 in the bank. He leaves it in the bank for 3 years. The interest is 7% each year. Calculate the simply interest and then the compound interest after 3 years. Principal value Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 66

67. S4 Credit www.mathsrevision.com Daniel has £400 in the bank. He leaves it in the bank for 3 years. The interest is 7% each year. Calculate the compound interest and the amount he has in the bank after 3 years. Y1 : Interest = 7% of £400 = £28 Amount = £400 + £28 = £428 Y 2 : Interest = 7% of £428 = £29.96 Amount = £428 + £29.96 = £457.96 Y 3 : Interest = 7% of £457.96 = £32.06 Amount = £457.06 + £32.06 = £490.02 Compound is £490.02 - £400 = £90.02Simple Interest is only £84 Interest = 7% of £400 = £28 3 x 28 = £84 Simple Interest Interest calculated on new value every year Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 67 Compound Interest

68. S4 Credit www.mathsrevision.com Easier Method Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 68 n = period of time Days, months years ± = increase or decrease I = initial value V = Value IMPORTANT Can only use this when percentage is fixed This is called the multiplier. Compound Interest

69. S4 Credit www.mathsrevision.com Calculate the money in the bank after 3 years if the compound interest rate is 7% and the initial value is £400. V= 400 x (1.07) 3 = £490.02 Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 69 n = 3 ± = increase 1+0.07=1.07 I =400 Compound Interest

70. S4 Credit Now try Ex 10.2 Ch2 (page 43) www.mathsrevision.com Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 70 Compound Interest

71. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Solve the equations Q2.Find the coordinates where the line and curve meet. www.mathsrevision.com

72. S4 Credit Learning Intention Success Criteria 1.To know the terms appreciation and depreciation. 1.To understand the terms appreciation and depreciation. 2.Show appropriate working when solving problems containing appreciation and depreciation. www.mathsrevision.com Appreciation & Depreciation Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 72

73. S4 Credit www.mathsrevision.com Appreciation : Going up in value e.g. House value Depreciation : Going down in value e.g. car value Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 73 Appreciation & Depreciation

74. S4 Credit Average house price in Ayr has appreciated by 79% over past 10 years. If you bought the house for £64995 in 1994 how much would the house be worth now ? Appreciation = 79% x £ 64995 = 0.79 x £64995 = £ 51346.05 New value = Old Value + Appreciation = £64995 + £51346.05 = £ 116341.05 Just working out percentages Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 74 Quicker Method Easier 1.79 x 64995 = £116341.05

75. S4 Credit Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 75 A Mini Cooper cost £14 625 in 2002 At the end 2003 it depreciated by 23% At the end 2004 it will depreciate by a further 16% What will the mini cooper worth at end 2004? End 2003 Depreciation = 23% x £14625 = 0.23 x £14625 = £3363.75 New value= Old value - Depreciation = £14625 - £3363.75 = £11261.25 www.mathsrevision.com Appreciation & Depreciation

76. S4 Credit www.mathsrevision.com Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 76 End 2003 Depreciation = 23% x £14625 = 0.23 x £14625 = £3363.75 New value= Old value - Depreciation New value= Old value - Depreciation = £14625 - £3363.75 = £11261.25 End 2004 Depreciation = 16% x £11261.25 = 0.16 x £11261.25 = £1801.80 New Value = £11261.25 - £1801.80 = £9459.45 = £9459.45 Appreciation & Depreciation

77. S4 Credit Now try MIA Ex 11.1 Ch2 (page 45) Odd Numbers www.mathsrevision.com Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 77 Appreciation & Depreciation

78. S4 Credit Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015Saturday, 02 May 2015 Starter Questions Q1.Solve the equations Q2.Solve the coordinates where the line and curve meet. www.mathsrevision.com

79. S4 Credit Learning Intention Success Criteria 1.To understand the process of work backwards. 1.To understand how to work backwards to find original price. 2.Solve problems using backwards process. www.mathsrevision.com Work Backwards Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 79

80. S4 Credit www.mathsrevision.com Example 1 After a 10% increase the price of a house is £88 000. What was the price before the increase. Price before is 100% :£800 x 100 = £80 000 1 % : 100 % + 10 % = £88 000Deduce from question : 110 % = £88 000We have : Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 80 Work Backwards

81. S4 Credit www.mathsrevision.com Example 2 The value of a car depreciated by 15%. It is now valued at £2550. What was it’s original price. Price before is 100% :£30 x 100 = £3 000 1 % : 100 % - 15 % = £2 550Deduce from question : 85 % = £2 550We have : Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 81 Work Backwards

82. S4 Credit Now try MIA Ex 11.2 Ch2 (page 46) www.mathsrevision.com Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015Saturday, May 02, 2015created by Mr. lafferty @ www.mathsrevision.com 82 Work Backwards