A train runs for 2 hours at 35 kmph, then 3 and a half hours at 60 kmph, and then 2 and a half hours at 70 kmph. Find its average speed.

A50 kmph

B55 kmph

C80 kmph

D56.87 kmph ✓ Correct

Correct answer: (D) 56.87 kmph

Explanation

The average speed is about 56.87 kmph.

Distances = 2 x 35 + 3.5 x 60 + 2.5 x 70 = 70 + 210 + 175 = 455 km.

Total time = 2 + 3.5 + 2.5 = 8 hours.

Average = total distance / total time = 455 / 8.

= 56.87 kmph.

Want more like this? Create a free account to practise a full test, track your progress, and get spaced-repetition review.