a 600 meter long train crosses a signal post in 60 seconds . how long will it take to cross a 3 kilometer long bridge , at the same speed ?
"s = 600 / 60 = 10 mps s = 3600 / 10 = 360 sec = 6 min answer : c"
divide(divide(multiply(3, const_1000), speed(600, 60)), const_60)