A car completes a journey in $10$ h, the first half at $21$km per hour, and the rest at $24$ km per hour. The distance travelled by the car is:

A man covers a certain distance on scooter. Had he moved $3$km/h faster, he would have taken $40$ min less. If he had moved $2$km/h slower, he would have taken $40$ min more. The distance (in km) is:

A car is ahead of a scooter by $30$ km. The car goes at the rate of $50$ km/h and the scooter goes at the rate of $60$ km/h. The scooter overtakes the car after:

Two runners cover the same distance at the rate of $15$ km and $16$ km per hour respectively. The distance travelled when one takes $16$ min longer than the other is:

The wheel of an engine, $3\frac{4}{7}$ metres in circumference, makes seven revolutions in three seconds. Find the speed of the train in km per hour.