Question

An ant completes moving along a circle in time 5s. How much time will it take to travel along the diameter and come back?

• A. 10s
• B. 6.36s
• C. 3.18s
• D. 5.26s

Answer 1

The correct option is C

3.18s

Take radius of the circle to be r.

First case, distance travelled = 2πr

Second case, distance travelled will be 4r.

As speed of ant is constant.

So, time taken will be proportional to distance travelled.

T= $\frac{4r}{2\pi r}$X 5

= $\frac{2}{\pi }$X 5

= 3.18 s