Question

There was a race held in your school and you wanted to watch the race and went to the ground. Three people started from A, B and C and stopped at the end point. Since the starting point is different for all, you felt that the game is not fair.

However, a friend of yours told you that the radius of the track B is more than radius of track A and hence everybody runs the same distance. He then asked you to find out the radius of track B, given that the radius of track A is 14m and distance between B and the end point is 22 m (as given in the figure). What is the radius of track B.

• A. 15 m
• B. 17.5 m
• C. 16 m
• D. 16.5 m

Answer 1

The correct option is B

17.5 m

The circumference of track A = 2 $\times \frac{22}{7}\times$ 14 = 88 m
The circumference of track B = circumference of track A + 22 m = 110 m
Let the radius of track B be r. So circumference of track B = 2πr
2πr = 110
2 $\times \frac{22}{7}\times r$ = 110

r = 17.5 m