the length of the bridge , which a train 200 metres long and travelling at 60 km / hr can cross in 30 seconds , is ?
"speed = [ 60 x 5 / 18 ] m / sec = [ 50 / 3 ] m / sec time = 30 sec let the length of bridge be x metres . then , ( 130 + x ) / 30 = 50 / 3 = > ( 130 + x ) / 30 = 370 = > x = 370 m . answer : d"
subtract(multiply(divide(multiply(60, speed(const_1000, const_1)), speed(const_3600, const_1)), 30), 200)