City E and City F is 450 km apart. Tim left City E for City F at 9.00 a.m. travelling at an average speed of 75 km/h. Oliver left City E later than Tim and caught up with him at 11.00 a.m. Oliver was travelling at a speed of 100 km/h.
- At what time did Oliver leave City E?
- How much later did Tim arrive in City F than Oliver? Express your answer in h as a fraction or mixed number.
(a)
From 9.00 a.m. to 11.00 a.m. = 2 h
Distance that Tim covered when Oliver caught up with Tim
= 2 x 75
= 150 km
Time that Oliver 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 Oliver left City E:
1 h 30 min before 11.00 a.m. = 9.30 a.m.
(b)
Remaining distance that they had to cover to reach City F
= 450 - 150
= 300 km
Duration that Oliver had to travel before reaching City F
= 300 ÷ 100
= 3 h
Duration that Tim had to travel before reaching City F
= 300 ÷ 75
= 4 h
Duration that Tim took to arrive later than Oliver in City F
= 4 - 3
= 1 h
Answer(s): (a) 9.30 a.m.; (b) 1 h