2022 · Q40
A train X takes 2 hours less than a train Y to cover a distance of 192 km between two cities. Their average speeds differ by 16 km/hr. How long does the faster train take to cover the journey?
Elementary MathematicsTime, Speed and Distance
- A3 hours
- B4 hours
- C5 hours
- D6 hours
Explanation
192/(s-16)-192/s = 2 gives s(s-16) = 1536, so s = 48 km/hr. The faster train takes 192/48 = 4 hours. Hence the keyed option is B.