CAT 2020 Slot 1 QA Question 13: A train travelled at one-thirds of its usual speed, and hence reached the destination 30 minutes after the scheduled time. On its return journey, the train initially travelled at its usual speed for 5

Question

A train travelled at one-thirds of its usual speed, and hence reached the destination 30 minutes after the scheduled time. On its return journey, the train initially travelled at its usual speed for 5

Accepted Answer

Let the usual speed be $v$ and the scheduled one-way time be $t$ minutes.

At one-third of the usual speed, the time taken becomes $3t$. The delay is 30 minutes.

$3t - t = 30$
$\Rightarrow 2t = 30$
$\Rightarrow t = 15$ minutes

On the return journey, the train first travels for 5 minutes at usual s