Question

A train travelling at a speed of 60 km/h leaves station A at 7:00 a.m. and another train travelling at a speed of 84 km/h starts from station A at 9:30 a.m. in the same direction on a parallel track. At what distance (in km) from station A and after how many hours of travel of the second train will they be together? Express your answer in the same order.

• A. 693 km, 8.25 hours
• B. 525 km, 6.25 hours
• C. 375 km, 6.25 hours
• D. 495 km, 8.25 hours

Answer 1

Answer:

B. 525 km, 6.25 hours

Given:

• Speed of first train = 60 km/h

• Speed of second train = 84 km/h

• First train starts at 7:00 a.m.

• Second train starts at 9:30 a.m.

  Head start of the first train

Time gap = 2.5 hours

Distance covered by first train in 2.5 hours:
$60 \times 2.5 = 150 \text{ km}$

Relative speed

$84 - 60 = 24 \text{ km/h}$

Time taken by second train to catch up

$\text{Time} = \frac{150}{24} = 6.25 \text{ hours}$

So, after 6.25 hours (6 hours 15 minutes) of travel of the second train, they meet.

Distance from station A

$84 \times 6.25 = 525 \text{ km}$

=525 km, 6.25 hours