Two trains each of length 50m. are running with constant speeds on parallel tracks. While moving in same direction one over takes the other in 40 seconds and while moving in opposite direction on ecrosses the other in 20 seonds. The speeds of trains will be:-

Options

A. `2.25ms^(-1)` and `2.75 ms^(-1)`
B. `2.15 ms^(-1)` and `2.85 ms^(-1)`
C. `3.75 ms^(-1)` and `1.25 ms^(-1)`
D. `4.25 ms^(-1)` and `0.75 ms^(-1)`

Answer

C

Explanation

`v_(1)-v_(2)=(100)/(40)=2.5`
`v_(1)+v_(2)=(100)/(20)=5`
Adding, `2v_(1)=7.5`
`rArrv_(1)=3.75` and `v_(2)=1.25`