Question

Three men start together to travel the same way around a circular track of 11 km. Their speeds are 4, 5.5 and 8 kmph respectively. When will they meet at the starting point for the first time?

(a) After 11 hours (b) After 21 hours (c) After 22 hours (d) After 33 hours

Answer 1

(c) Let the minimum time be t, when they meet at the starting point for the first time.

So, the net distance covered must be a multiple of 11.

Now, (4 + 5.5 + 8) t = 11 (n)

where, n is an integer.

minium value of n is 35, so that we can get an appropriate value of time.