Question

A train covers a distance of 90km at a uniform speed . Had the speed been 15km/h more, it would have taken 30min less for the journey. then the original speed of the train =

Answer 1

Distance= 90*t
dis= 105* (t-0.5)
90t = 105t - 105/2
15t == 105/2
t = 105/30 = 3.5 h

dis= 90* 105/30= 315km
actual speed =315/3 =105 kmh