Question

a man travels 370 km partly by train and partly by car.if he travels 250 km by train and reat by car it takes him 4 hours but if he travels 130 km by train and rest by car he takes 18 min longer . find speed of both train an car

Answer 1

total distance = 370 km let the speed of train be X km/hr and car be y km/hr

then , (time = distance by speed ) => t1 = 250 / x and t2 = 120/y

then , 250/x + 120/y = 4 ..........................(1)

similarly , 130/x + 240/y = 258/60 ..............(2)

then , let 1/x be u and 1/y be v

then , 250u +120v =4

and 130u + 240 v = 258 /60

then , 130(250u +120 v =4)

250(130u +240 v = 258/60)

then , 32500 u + 15600 v = 520

32500 u + 60000v = 1075

then , -44400 v = -555 =>v = 1/80 or y = 80 km/hr

and x = 250/x + 120/80 = 4 => x = 250 /x = 4 - 3/2 => 250 /x = 5/2 => 5x = 500 = x =100 km/hr