Guru and Chela walk around a circular path of 115 km in circumference, they start together from the same point. If they walk at speed of 4 and 5 kmph respectively, also they walk in the same direction, when will they meet?

Solution

If two persons moving with speeds of X kmph and Y kmph on a circular path of P km in the same direction from the common starting point, then they meet for first time after $$\dfrac{\ P}{\left|X-Y\right|}\ hrs$$.

In this question, P = 115 km; |X-Y| = |5-4| = 1 kmph

Therefore, they meet for first time after 115 hrs.