Rate and Ratio
- A ratio is a comparison of quantities
For example, 3 dogs to 7 cats is 3:7
- An equivalent ratio can be formed by
multiplying or dividing the terms of a ratio by the same number.
For example:
5:8
= (5x3): (8x3)
= 15:24
5:8 and 15:24 are equivalent ratios
36:30
= (366): (306)
= 6:5
36:30 and 6:5 are equivalent ratios
- Two ratios can be compared when the second
terms are the same. For example, Scott’s scoring record was 16:5. Brittany’s
scoring record was 10:3. To find who had the better record, used equivalent
ratios to make the second term of each ratio 15.
Scott
16:5
= (16x3):(5x3)
= 48:15
Brittany
10:3
= (10x5):(3x5)
= 50:15
Brittany had the better record.
- A rate is a comparison of two quantities with
different units.
For example: Heart rate is measured in beats per minute (beats/minutes). Average speed is measured in kilometers per hour (km/h). Fuel consumption of an aircraft is measured in liters per hour (L/h).