The van still had 72km to travel when the car arrived. It would use 1½ h to do that and therefore arrive 1½ hours later than the car.

So this tells you that the van travels 72km in 1½ hours.

Speed of van = 72km ÷ 1½h
= 48km/h

Time the van taken for the whole journey
= 216km ÷ 48km/h
= 4½h

Car took 1½ h less to reach, so car used
4½ h - 1½h = 3h

Speed of car

= 216km ÷ 3h
= 72km/h




Alternatively,

Distance van had travelled when car reached

= 216km - 72km
= 144km


144km ÷ 216km = 2/3

The van travelled ⅔ the distance the car travelled in the same time


So it's speed is ⅔ as fast as the the car.

Car speed = 48km/h ÷ 2 x 3 = 72km/h

Or

48km/h ÷ ⅔ = 72km/h