two trains 200 m and 150 m long are running on parallel rails at the rate of 40 kmph and 42 kmph respectively . in how much time will they cross each other , if they are running in the same direction ?
"solution relative speed = ( 42 - 40 ) kmph = 2 kmph = ( 2 x 5 / 18 ) m / sec = ( 10 / 18 ) m / sec time taken = ( 350 x 18 / 10 ) sec = 630 sec . answer e"
multiply(const_3600, divide(divide(add(200, 150), const_1000), subtract(42, 40)))