Exercise 6 Page 13

We are given the following table.

Name	Event	Time (s)
Tawni	50-m Freestyle	40.8
Pepita	100-m Butterfly	60.2
Susana	200-m Medley	112.4

We want to determine who swam the fastest. Let's find the average speed of each person from the table. We will find how many meters per second each person swam. Let's start with Tawni. We know that she swam 50 meters in 40.8 seconds. We can write a rate to show this situation. 50 m/40.8sRecall that a unit rate is a rate that has been reduced to a denominator of 1 unit. In this case, the unit rate is the number of meters per 1 second. Let's find the unit rate! For simplicity, we can temporarily ignore the units.

50/40.8

ReduceFrac

a/b=.a / 40.8./.b / 40.8.

50/ 40.8/40.8/ 40.8

UseCalc

Use a calculator

1.225490.../1

RoundDec

Round to 2 decimal place(s)

1.23/1

Finally, we got the unit rate. 50 m/40.8s ≈ 1.23 m/1s As we can see, Tawni's average speed is about 1.23 meters per second. We can find Pepita's and Susana's speeds by following the same steps.

Name	Event	Time (s)	Rate	Unit Rate
Tawni	50-m Freestyle	40.8	50m/40.8s	50m ÷ 40.8/40.8s ÷ 40.8 ≈ 1.23m/1s
Pepita	100-m Butterfly	60.2	100m/60.2s	100m ÷ 60.2/60.2s ÷ 60.2 ≈ 1.66m/1s
Susana	200-m Medley	112.4	200m/112.4s	200m ÷ 112.4/112.4s ÷ 112.4 ≈ 1.78m/1s

As we know, the unit rate is the number of meters per second swum by each person from the table.

Name	Unit Rate	Average Speed
Tawni	≈ 1.23m/1sec	≈ 1.23 meters per second
Pepita	≈ 1.66m/1sec	≈ 1.66 meters per second
Susana	≈ 1.78m/1sec	≈ 1.78 meters per second

We can see that Susana has the greatest average speed. This means that she swam the fastest!