A car starts from point A towards point B, travelling at the speed of 20 km/h. 1hours later, another car starts from point A and travelling at the speed of 30 km/h and reaches 2hours before the first car. Find the distance between A and B.

Question

Question

This question was previously asked in

SSC CGL 2022 Tier-I Official Paper (Held On : 03 Dec 2022 Shift 1)

Answer 1

Given:

A car starts from point A towards point B, travelling at the speed of 20 km/h.

1hours later, another car starts from point A and travelling at the speed of 30 km/h and reaches 2hours before the first car.

Concept used:

Total distance =

Here,

S₁ = speed of the faster object

S₂ = speed of the slower object

T₁ = Time1

T₂ = Time 2

Calculation:

According to the concept,

Total distance =

⇒

⇒ 240 km

∴ The distance between A and B is 240 km.

Alternate Method

Let the total distance be x km,

In 1.5 hr 1st car travel 30 km, remaining (x - 30) km

So, according to the question.

⇒ = 2.5

⇒ x - 90 = 150

⇒ x = 240 km