Question

Runner A takes 45seconds to run 400m. Runner B takes 48seconds to run the same distance. Which runner has the greater average speed?

Answer 1

Answer:

A:400/45

 =80/9

B:400/48

=100/12

=25/3

Comparision: a:b

                      80/9 : 75/9

Runner A has more avg. speed.

Answer 2

Answer:

Runner A

Explanation:

>Runner A:

Time         = 45s

Distance   = 400m

A. Speed  = $\frac{Distance}{Time}$

                 = $\frac{400}{45}$

                 = 8.888888889m/s

>Runner B:

Time         = 48s

Distance   = 400m

A. Speed  = $\frac{Distance}{Time}$

                 = $\frac{400}{48}$

                 = 8.333333333m/s

> Compare both averages:

   Runner A     :    Runner B

8.888888889 : 8.333333333

∴Runner A has a greater average speed.

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[I hope this is right]