Question

Time is taken by two trains running in opposite directions to cross a man standing on the platform in 25 seconds and 15 seconds respectively. It took 18 seconds for the trains to cross each other. What is the ratio of their speeds?

A 2:3 Correct Answer Incorrect Answer
B 5:7 Correct Answer Incorrect Answer
C 1:3 Correct Answer Incorrect Answer
D 3:7 Correct Answer Incorrect Answer

Solution

Let the speed one train be x m/s and the speed of the second train be y m/s. Length of the first train = Speed × Time = 25x Length of second train = Speed × Time = 15y So, {(25x + 15y)/(x+y)} = 18 ⇒  25x + 15y = 18x + 18y ⇒  7x = 3y Therefore, x:y = 3:7

Practice Next

Relevant for Exams:

×
×