a train which has 400 m long , is running 50 kmph . in what time will it cross a person moving at 14 kmph in same direction ?
"time taken to cross a moving person = length of train / relative speed time taken = 400 / ( ( 50 - 14 ) ( 5 / 18 ) = 400 / 36 * ( 5 / 18 ) = 400 / 10 = 40 sec answer : a"
divide(400, subtract(divide(50, const_3_6), divide(divide(14, const_2), const_3_6)))