The train takes 50 minutes for the journey if it runs at 48 km/hour, the rate at which the train must run to reduce the time to40 minutes will be:

A) 50 km/hr

B) 55 km/hr

C) 60 km / hr ✓

D) 57 km/hr

Solution(By Preparationpoint Team)

Speed (S) = 48 kmph.

Time (T) = 50 min = 50/60 = 5/6 hours.

New Speed  = s (let).

New Time (t) = 40 min = 40/60 = 2/3 hours.

A _______________________D_________________________B

When distance is constant, Time is inversely proptional to speed.

S/s = t/T

48 /s = (2/3)/(5/6)

48/s = 4/5

4s = 48 *5

s = (48 *5)/ 4 = 60 kmph.