a goods train leaves a station at a certain time and at a fixed speed . after ^ hours , an express train leaves the same station and moves in the same direction at a uniform speed of 90 kmph . this train catches up the goods train in 4 hours . find the speed of the goods train .
let the speed of the goods train be x kmph . distance covered by goods train in 10 hours = distance covered by express train in 4 hours 10 x = 4 x 90 or x = 36 . so , speed of goods train = 36 kmph . ans : b
divide(multiply(90, 4), add(4, add(const_3, const_3)))