Two trains started at the same time, one from A to B and other from B to A. if they arrived at B and A respectively in 4 hours and 9 hours after they passed each other, the ratio of the speeds of the two trains was:

A. 2 : 1

B. 3 : 2

C. 4 : 3

D. 5 : 4

Answer: Option B

Solution(By Examveda Team)

A →____________________← B
Ratio of the speed of trains is given by;
$$\eqalign{ & \frac{{{\text{Speed}}\,{\text{of}}\,{\text{train}}\,A}}{{{\text{Speed}}\,{\text{train}}\,{\text{of}}\,B}} = \frac{{\sqrt B }}{{\sqrt A }} \cr & = \frac{{\sqrt 9 }}{{\sqrt 4 }} \cr & = \frac{3}{2} \cr & = 3:2 \cr} $$