Multiple choice

Mr. Muneesh went from A to B via C with an average speed of 20 kmph between A and C and 30 kmph between C and B. If he travels at 30 kmph between A and C and 20 kmph between C and B, it takes 2 hours less time to reach B. If the distance between C and B is 120 km, what is the distance between A and C?

  1. 120 km

  2. 200 km

  3. 300 km

  4. 240 km

  5. 360 km
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let d1 = distance AC and d2 = 120 km (CB). Time 1 = d1/20 + 120/30 = d1/20 + 4. Time 2 = d1/30 + 120/20 = d1/30 + 6. Given Time 1 - Time 2 = 2, so (d1/20 + 4) - (d1/30 + 6) = 2. d1/20 - d1/30 = 4. d1/60 = 4, so d1 = 240.

AI explanation

The time difference between the two scenarios is 2 hours, so using the time formula we write (D/20) + (120/30) minus ((D/30) + (120/20)) equals 2. Simplifying this time difference equation gives (D/20 minus D/30) plus (4 minus 6) equals 2. This results in D/60 minus 2 equals 2, meaning D/60 equals 4. The distance between A and C is 4 multiplied by 60, which is 240 km.

Keep practicing — related questions