Question

An aeroplane covers a certain distance at a speed of 240km/h in 5 hours. To cover the same distance in 1 2/3 hours, it must travel at the speed of.

Answer 1

720 km/h

Explanation:

distance = 240*5=1200km

speed = distance/time

=1200/1.33 = 720 km/h

Answer 2

720 kph

Explanation:

The ratio of times is ...

new time/original time = (1 2/3 h)/(5 h) = (5/3 h)/5 h) = 1/3

For the same distance, the ratio of speeds must be the inverse of this:

new speed/original speed = s/240 = 1/(1/3) = 3

s = 240(3) = 720 . . . . km/h

The aeroplane must travel at a speed of 720 km/h.