Multiple choice

With an average speed of 40 km/hr. a train reaches its destination on time.If it goes with an average speed of 35 km./hr. it is late by 15 minutes.The total journey is -

  1. 80 km.

  2. 40 km.

  3. 70 km.

  4. 30 km.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let distance = d km. At 40 km/h: time = d/40 hours. At 35 km/h: time = d/35 hours. Difference = 15 min = 0.25 hours. So d/35 - d/40 = 0.25. Solving: d(1/35 - 1/40) = 0.25 → d(5/1400) = 0.25 → d = 0.25 × 280 = 70 km. At 70 km, time at 40 km/h = 1.75 hr; at 35 km/h = 2 hr (15 min late).

Keep practicing — related questions