Question

Rajdhani Express Leaves Mumbai Towards Delhi At 3.10Pm. And Travels Uniformly At 120 Kmph. August Kranti Express Leaves Delhi Towards Mumbai At 12.20 Pm. And Travels Uniformly At 80 Kmph. Both Trains Cross At Baroda At 4.30. Pm. On A Particular Day, Rajdhani Express Leaves At 3:20 Pm. When Will The Two Trains Cross

Answer 1

Hey Dear,

◆ Answer -

Trains will cross at 4:36 pm

● Explaination -

Let s be distance between Delhi and mumbai.

When two trains cross, s will be sum of distance covered by them.

s = v1.t1 + v2.t2

s = 120(4:30-3:10) + 80(4:30-12:20)

s = 120(1.33) + 80(4.17)

s = 493 m

When Rajdhani express leaves at 3:20 pm -

s = v1.t1 + v2.t2

493 = 120(t-3:20) + 80(t-12:20)

493 = 120t - 120×3.33 + 80t - 80×0.33

200t = 493 + 400 + 26.67

200t = 919.67

t = 4.6 = 4:36 pm

Therefore, two trains will cross at about 4:36 pm.

* Note min to hour conversion here, 1 min = 1/60 hr

Thanks...