Question

A plane left 30 minutes later than the schedule time and in order to reach its destination 1500 km away in time it has to increase its speed by 250 km/h from its usual speed. Find its usual speed.

Answer 1

Let the usual speed of plane be x km/hr
∴ Increased speed = (250 + x) km/hr

Time taken to cover 1500 km at usual speed =1500/x

Time taken to cover 1500 km at increased speed = 1500/(x+250)