2016 · Q47
In a race of 1000 m, A beats B by 100 m or 10 seconds. If they start a race of 1000 m simultaneously from the same point and if B gets injured after running 50 m less than half the race length and due to which his speed gets halved, then by how much time will A beat B?
Elementary MathematicsTime, Speed and Distance
- A65 seconds
- B60 seconds
- C50 seconds
- D45 seconds
Explanation
B covers 100 m in 10 s, so B's speed is 10 m/s and A's 1000 m time is 90 s. Injured after 450 m, B takes 45 s for the first 450 m and 110 s for the remaining 550 m at halved speed — 155 s total. A beats B by 155−90 = 65 s, option A.