Multiple choice

A man has to be at a certain place at a certain time. He finds that he shall be 20 minutes late if he walks at 3 km/h speed and 10 minutes earlier if he walks at a speed of 4 km/hr. Find the distance that he has to walk.

  1. 24 km

  2. 12.5 km

  3. 10 km

  4. 6 km
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let distance be D. Time at 3 km/h = D/3. Time at 4 km/h = D/4. Difference = 20 min + 10 min = 30 min = 0.5 hours. D/3 - D/4 = 0.5. D/12 = 0.5. D = 6 km.

AI explanation

Let the scheduled time be t hours, so the time taken at 3 km/hr is (t + 1/3) hours and the time at 4 km/hr is (t - 1/6) hours. Since the distance is constant, 3(t + 1/3) = 4(t - 1/6), which solves to t = 3 hours. Substituting this into the first distance equation yields a distance of 3 * (3 + 1/3) = 6 km.

Keep practicing — related questions