City P and City Q is 480 km apart. Carl left City P for City Q at 10.00 a.m. travelling at an average speed of 60 km/h. Billy left City P later than Carl and caught up with him at 2.00 p.m. Billy was travelling at a speed of 96 km/h.
- At what time did Billy leave City P?
- How much later did Carl arrive in City Q than Billy? Express your answer in h as a fraction or mixed number.
(a)
From 10.00 a.m. to 2.00 p.m. = 4 h
Distance that Carl covered when Billy caught up with Carl
= 4 x 60
= 240 km
Time that Billy took to travel 240 km
= 240 ÷ 96
= 2
12 h
1 h = 60 min
12 h =
12 x 60 = 30 min
2
12 h = 2 h 30 min
Time that Billy left City P:
2 h 30 min before 2.00 p.m. = 11.30 a.m.
(b)
Remaining distance that they had to cover to reach City Q
= 480 - 240
= 240 km
Duration that Billy had to travel before reaching City Q
= 240 ÷ 96
= 2
12 h
Duration that Carl had to travel before reaching City Q
= 240 ÷ 60
= 4 h
Duration that Carl took to arrive later than Billy in City Q
= 4 - 2
12= 1
12 h
Answer(s): (a) 11.30 a.m.; (b) 1
12 h
