Multiple choice

A train of length 250 m crosses a lamppost in 10 seconds. What should be the increase in the speed of the train so that it can cover a distance of 1350 km in 10 hours?

  1. 50%

  2. 75%

  3. 60%

  4. 40%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Current speed = 250m / 10s = 25 m/s. Convert to km/h: 25 * (18/5) = 90 km/h. Required speed = 1350 km / 10 h = 135 km/h. Increase = 135 - 90 = 45. Percentage increase = (45 / 90) * 100 = 50%.

AI explanation

The initial speed of the train is 250 divided by 10, which equals 25 m/s, and converting to km/h gives 25 multiplied by 18/5 to equal 90 km/h. The required speed to cover 1350 km in 10 hours is 1350 divided by 10, which equals 135 km/h. The increase in speed is 135 minus 90, resulting in a 45 km/h increase, which is a 50 percent increase over the initial speed.

Keep practicing — related questions