City V and City W is 450 km apart. Pierre left City V for City W at 10.00 a.m. travelling at an average speed of 75 km/h. Zeph left City V later than Pierre and caught up with him at 12.00 p.m. Zeph was travelling at a speed of 100 km/h.
- At what time did Zeph leave City V?
- How much later did Pierre arrive in City W than Zeph? Express your answer in h as a fraction or mixed number.
(a)
From 10.00 a.m. to 12.00 p.m. = 2 h
Distance that Pierre covered when Zeph caught up with Pierre
= 2 x 75
= 150 km
Time that Zeph took to travel 150 km
= 150 ÷ 100
= 1
12 h
1 h = 60 min
12 h =
12 x 60 = 30 min
1
12 h = 1 h 30 min
Time that Zeph left City V:
1 h 30 min before 12.00 p.m. = 10.30 a.m.
(b)
Remaining distance that they had to cover to reach City W
= 450 - 150
= 300 km
Duration that Zeph had to travel before reaching City W
= 300 ÷ 100
= 3 h
Duration that Pierre had to travel before reaching City W
= 300 ÷ 75
= 4 h
Duration that Pierre took to arrive later than Zeph in City W
= 4 - 3
= 1 h
Answer(s): (a) 10.30 a.m.; (b) 1 h