SSC CGL 2022 PYQ — Question 57

The correct answer is Option 3 i.e. 22.5 km.

Given:

Moving with 45 km/h, train reaches on time.

Moving with 30 km/h train reaches 15 minutes late.

Concept Used:

Distance = speed × time

Explanation:

Let the time taken by train to reach the destination on time is t hours.

Then, distance = 45t    ...(i)

Now, the time taken by train while travelling with 30 km/h speed = t + $15\over60$ = $(t + {1\over 4})$ hours

Then, distance = $30(t + {1\over 4})$   ...(ii)

Equating equation (i) and equation (ii), we get

45t = $30(t + {1\over 4})$

⇒ 45t = 30t + $15 \over 2$

⇒ 15t = $15 \over 2$

⇒ t = $1\over 2$ ⇒ 30 minutes.

Now distance = 45 × $1\over 2$ = 22.5 Km.

Hence the total journey is 22.5 km.