Multiple choice

Terry plans a vacation with his friends to travel form Mumbai to Goa. They travel the distance at a speed of 120 km/hr. They decide to come back on a busy weekend due to which they are able to travel at a speed of 90 km/hr. The entire journey took them 7 hours 35 minutes, travelling both ways. How many kilometres they travelled one way?

  1. 390 km

  2. 400 km

  3. 415 km

  4. 545 km

  5. 600 km

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let distance be d. Time = d/120 + d/90 = 7 hours 35 minutes = 7 + 35/60 = 7 + 7/12 = 91/12 hours. (3d + 4d) / 360 = 91/12. 7d / 360 = 91/12. d = (91 * 360) / (12 * 7) = 13 * 30 = 390 km.

AI explanation

Let the one way distance be d kilometres; using the time formula, time equals distance divided by speed. The total time of 7 hours and 35 minutes converts to 7 and 35/60 hours, or 152/12 hours. The equation is (d/120) + (d/90) = 152/12, which simplifies to (3d + 4d)/360 = 152/12. Solving for d gives 7d/360 = 152/12, so d = (152 multiplied by 360) divided by (12 multiplied by 7), resulting in a one way distance of 390 km.