2015 · Q53
The speeds of three buses are in the ratio 2:3:4. The time taken by these buses to travel the same distance will be in the ratio
Elementary MathematicsMensuration
- A2:3:4
- B4:3:2
- C4:3:6
- D6:4:3
Explanation
This tests the inverse relationship between speed and time. For a fixed distance, time = distance/speed, so the times are in the ratio 1/2 : 1/3 : 1/4. Multiplying through by the LCM 12 gives 6:4:3. The trap is option (a) 2:3:4, the direct ratio; the fastest bus takes the least time, so the time ratio must reverse the speed ratio. Hence option (d).