1. RATES

2. RaTEs
A rate is a ratio that compares quantities measured in different units. For example, the speed of a car is measured in km/h (kilometres per hour).
The ‘per’ symbol (/) is also a form of division.
Rates may be calculated by dividing the two quantities measured.

3. Example #1:
What is the average speed of a car that travelled 360km in 4 hours?
Average speed (km/h)
= 360km / 4h
= 360 divided by 4
= 90km/h

4. Example #2:
What is the run rate of a one-day cricket team that scored 300 runs in 50 overs?
Run rate (runs/over)
= 300 runs / 50 overs
= 300 divided by 50
= 6 runs/over

5. HOMEWORK: Complete proportion worksheet
In your Math journal, complete all questions on pg 82/83. Show your working out.

6. Converting Units of Measurement:
Some rate problems will involve different units of measurement.
Remember, when solving rate problems all RATIOS must be in PROPORTION (equal measurements).

7. COMMON UNITS:
mm-cm-m-km 10mm=1cm 100cm=1m 1000m=1km ml-L 1000ml=1L g-kg 1000g=1kg sec-mins-hours 60secs=1 minute 3600secs=1 hour

8. PRACTICE PROBLEMS: Solve these problems involving rates:
What is the average speed of a train that travelled 600km in 3 hours?
What is the cost per minute of an 8 minutes phone call costing $2.40?
Mr James ran 26 kilometres in 2 and a half hours. How fast did he run per hour? How fast did he run per minute?
2. Solve these problems involving rates:
What is the cost per metre of 7m of rope that costs $21?
A driver takes 10 hours to travel from Sydney to Melbourne. What is the average speed for this 880km trip?
The UAE needs 81 runs in the next 9 overs to win a one-day cricket match. What run rate is required?
The 1400km plane ride from Sharjah to Egypt takes 3 hours. What is the average speed of the aircraft?
A patient’s heart beats 360 times in 5 minutes. What is the patient’s heart rate in beats per minute?
A 20 litre can of paint costs $80. What is the cost per litre?
A taxi driver paid $90 for 60L of fuel. What is the cost per litre?