A van leaves at 8:00 a.m. at 40 km/h. A car leaves the same place at 9:00 a.m. on the same road at 60 km/h. How many hours after leaving does the car catch up?
Correct answer: B. 2 hours
By 9:00 a.m. the van is 40 km ahead. The car gains 60 − 40 = 20 km each hour, so it catches up after 40 ÷ 20 = 2 hours, at 11:00 a.m.
hard