Two trains of equal length take 10 s and 20 s…

Two trains of equal length take 10 s and 20 s, respectively, to cross a pole. If these trains are moving in the same direction, then how long will it take to cross each other?

Show answer & explanation

Correct answer: C

Explanation

The correct answer is Option 4 i.e. 40 sec.

Let the length of each train = x

Speed of 1st train = $x\over10$

Speed of 2nd train = $x\over20$

Relative speed = $x\over10$ - $x\over20$ = $x\over20$

Time to cross each other = $x+x\over{x\over20}$ = $2x\over{x\over20}$ = 40 seconds

SSC Selection Post 2024 PYQ — Question 61