two trains of length 120 meter and 150 meter crosses a stationary man in 10 and 15 seconds respectively . in what time they will cross each other when they are moving in same direction .
explanation : 120 = a * 10 , a = 12 m / sec ( speed of first train ) 150 = b * 15 , b = 10 m / sec ( speed of second train ) 270 = ( 2 ) * t , t = 135 seconds answer – c
divide(add(150, 120), subtract(divide(120, 10), divide(150, 15)))