City L and City M is 546 km apart. Charlie left City L for City M at 7.00 a.m. travelling at an average speed of 78 km/h. Fred left City L later than Charlie and caught up with him at 9.00 a.m. Fred was travelling at a speed of 104 km/h.
- At what time did Fred leave City L?
- How much later did Charlie arrive in City M than Fred? Express your answer in h as a fraction or mixed number.
(a)
From 7.00 a.m. to 9.00 a.m. = 2 h
Distance that Charlie covered when Fred caught up with Charlie
= 2 x 78
= 156 km
Time that Fred took to travel 156 km
= 156 ÷ 104
= 1
12 h
1 h = 60 min
12 h =
12 x 60 = 30 min
1
12 h = 1 h 30 min
Time that Fred left City L:
1 h 30 min before 9.00 a.m. = 7.30 a.m.
(b)
Remaining distance that they had to cover to reach City M
= 546 - 156
= 390 km
Duration that Fred had to travel before reaching City M
= 390 ÷ 104
= 3
34 h
Duration that Charlie had to travel before reaching City M
= 390 ÷ 78
= 5 h
Duration that Charlie took to arrive later than Fred in City M
= 5 - 3
34= 1
14 h
Answer(s): (a) 7.30 a.m.; (b) 1
14 h