Question

Two friends A and B are 30 km apart and they start simultaneously on motorcycles to meet each other. The speed of A is 3 times that of B. The distance between them decreases at the rate of 2 km per minute. Ten minutes after they start, A'* vehicle breaks down and A stops and waits for B to arrive. After how much time (in minutes) A started riding, does B meet A?

(A) 15

(B) 20

(C) 25

(D) 30

Answer 1

Correct option (D) 30

Explanation:

Speed of B = V km/hr

Speed of A = 3V km/hr

Given 4V = 2 × 60 km/hr

⇒ V = 30 km/hr

Distance covered by then after 10 min = 2 × 10 = 20 km

so remaining distance = (30 – 20) km = 10 km

Time taken by B to cover 10 km = 10/30/60 = 20 min.

Total time = 20 +10= 30min