Question

An athlete trains on a circular track of radius 40 m and jogs 10 laps each day, 5 days a week. How far does he jog each week? Round the answer to the nearest whole number of metres.

Answer 1

Length of a circle=2πr
r=40 m
Length of the circular track=2*π*40m=80π m.

The athelete jogs each day 10 laps
1 lap-------------------80π m
10 laps-------------   x
x=(10 laps * 80π m) / 1 lap=800π m

Calculate how far he jog eache week (5 days).
1 day------------------800π m
5 days----------------   x
x=(5 days*800π m)/1day=4000π m=4000m * 3.141592...≈12566,37 m

solution: 12566 m