1. Unit 6. Day 11.

2. Six Examples

3. Original Amount % Change New Amount
Example A: Disneyland increased the price of popcorn from $4 to $5. Find the percent increase. $4 ? $5
Example B: A $48 video game is increased by 25%. What is the new price?
$48 ?
25%
Example C: A new car costs $24,000 after an 20% increase. What was the original price?
$24000
20% ?

4. Example A: Disneyland increased the price of popcorn from $4 to $5
Example A: Disneyland increased the price of popcorn from $4 to $5. Find the percent increase. 4
increase
100 𝑥 1
increase =
original 4
original 4𝑥 =
100 4 4
100 4
50 2 𝑥 = = = 25
amount of increase 1
0.25
% increase = =
original amount
25%

5. Example B: A $48 video game is increased by 25%. What is the new price?𝑥
increase
25 100 =
increase
125 𝑥
new price
new % = 48
original
original
100 48
old price
old %
25 48
1200 =
100 𝑥
100𝑥
6000 =
100𝑥
100
100
100
100 12 12 = 𝑥 60 = 𝑥
$ 4 8 +
$ 1 2
6 0

6. Example C: A new car cots $24,000 after an 20% increase
Example C: A new car cots $24,000 after an 20% increase. What was the original price?
increase
new
120 20
24000
24000
increase
new =
100 𝑥
original
100 𝑥
original
= 𝑥 6𝑥 =
120000 6 6 𝑥 =
20,000

7. Original Amount % Change New Amount
Example D: Mr. Jordan’s sleep decreased from 8 hours per night to 5 hours per night. Find the percent decrease. 8 ? 5
Example E: A $40 pair of jeans goes on sale and is decreased by 15%. What is the new price?
$40 ?
15%
Example F: A new DVD costs $18 after an 25% decrease. What was the original price?
$18
25% ?

8. Example D: Mr. Jordan’s sleep decreased from 8 hours per night to 5 hours per night. Find the percent decrease. 8
decrease
100 𝑥 3
decrease =
original 8
original 8𝑥 =
300 8 8
300 8
150 4
37.5
37.5 𝑥 = = =
amount of decrease =
% decrease =
0.375
original amount
37.5% 8 − 5 3 3

9. Example E: A $40 pair of jeans goes on sale and is decreased by 15%
Example E: A $40 pair of jeans goes on sale and is decreased by 15%. What is the new price? 𝑥
decrease
15 100
decrease = 40 𝑥
original
original
sale = 85
sale
100 40
original
original
15 40
600 =
100 𝑥
100𝑥
100
100
3400 =
100𝑥
100
100 6 6 = 𝑥 34 = 𝑥
$ 4 0 −
$ 6
3 4

10. Example F: A new DVD costs $18 after an 25% decrease
Example F: A new DVD costs $18 after an 25% decrease. What was the original price? 18 18
decrease
new 75 25
decrease
new =
100 𝑥
100 𝑥
original
original
3 4 = 18 𝑥 3𝑥 = 72 3 3 𝑥 = 24