An aeroplane covers a certain distance at a speed of 240 kmph in 5 hours. To cover the same distance in $1\frac{2}{3}$ hours, it must travel at a speed of:

A. 300 kmph

B. 360 kmph

C. 600 kmph

D. 720 kmph

Correct Answer :

D. 720 kmph

Distance = (240 x 5) = 1200 km. Speed = Distance/Time Speed = 1200/(5/3) km/hr. [We can write $1\frac{2}{3}$ hours as 5/3 hours] $\therefore Requiredspeed=\left(1200x\frac{3}{5}\right)km/hr=720km/hr.$