Question

A lorry covers a distance in 25 min, if it runs at a speed of 24 kmph on an average. The speed at which the lorry must run to reduce the time of journey to 20 min will be

• A. 30 kmph
• B. 60 kmph
• C. 40 kmph
• D. 45 kmph
• E. 20 kmph

Answer 1

The correct option is A

30 kmph

$Time=\frac{25}{60}hours=\frac{5}{12}hoursSpeed=24kmph$
$Distance=Speed\times Time=24\times \frac{5}{12}=10km$
$Newtime=\frac{20}{60}hours=\frac{1}{3}hours$
$Newspeed=10\times 3kmph=30kmph$