Question

two trains start from the same station at 11 pm in opposite direction at speeds of 72 km/h and 63 km/h respectively .at what time they will be 810km apart?

Answer 1

Solution :

since start every hour they will be 72+63 =135 km apart

so to be 810 km apart = 810 / 135 = 6 hours

so 6 hrs from 11 P.M would be 5 A.M

so at 5 A.M they will be 810 km apart

hope that helps !!!