a train of length 240 m crosses a bridge of length 150 m in 20 seconds . what is the speed of train ?
"sol : ( length of train + length of bridge ) = speed of train x time ( 240 + 150 ) = 20 x speed speed = 390 / 20 = 19.5 m / s = 70.2 km / h answer = d"
multiply(const_3_6, divide(add(240, 150), 20))