Question

A and B are two stations 370 km apart. A train starts from station A at 9:00 A.M. and travels towards station B at a speed of 20 km/hr. Another train starts from station B at 10:00 A.M. and travels towards station A at a speed of 50 km per/hr. At what time do they meet?

• A. 3:00 PM
• B. 2:30 PM
• C. 2:00 PM
• D. 1:00 PM

Answer 1

Answer:

A. 3:00 PM

Step 1: Understand the problem

• Distance between A and B = 370 km

• Train 1 (from A): 9:00 AM, speed = 20 km/h

• Train 2 (from B): 10:00 AM, speed = 50 km/h

We are asked: At what time do they meet?

Step 2: Distance traveled by Train 1 before Train 2 starts

• Train 1 starts at 9:00 AM

• Train 2 starts at 10:00 AM → 1 hour later

$\text{Distance traveled by Train 1 in 1 hour} = 20 \times 1 = 20 \text{ km}$

• Remaining distance between them at 10:00 AM = 370 − 20 = 350 km

  Step 3: Relative speed after 10:00 AM

• Trains are moving towards each other → relative speed = 20 + 50 = 70 km/h

  Step 4: Time to meet after 10:00 AM

  
  $\text{Time} = \frac{\text{Distance}}{\text{Relative speed}} = \frac{350}{70} = 5 \text{ hours}$

  Step 5: Meeting time

• 5 hours after 10:00 AM → 3:00 PM

The trains meet at 3:00 PM