2018 · Q43
A thief steals a car parked in a house and goes away with a speed of 40 kmph. The theft was t discovered after half an hour and immediately the owner sets off in another car with a speed of 60 kmph. When will the owner meet the thief ?
Elementary MathematicsTime, Speed and Distance
- A55 km from the owner’s house and one hour after the theft
- B60 km from the owner’s house and 1.5 hours after the theft
- C60 km from the owner’s house and 1.5 hours after the discovery of the theft
- D55 km from the owner’s house and 1.5 hours after the theft
Explanation
The thief's half-hour head start at 40 kmph is 20 km. The relative speed is 60 - 40 = 20 kmph, so the owner catches up in 20/20 = 1 hour, i.e. 1.5 hours after the theft. Distance from the house = 60 x 1 = 60 km. Hence option B.