City L and City M is 414 km apart. George left City L for City M at 7.00 a.m. travelling at an average speed of 69 km/h. Luis left City L later than George and caught up with him at 9.00 a.m. Luis was travelling at a speed of 72 km/h.
- At what time did Luis leave City L?
- How much later did George arrive in City M than Luis? 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 George covered when Luis caught up with George
= 2 x 69
= 138 km
Time that Luis took to travel 138 km
= 138 ÷ 72
= 1
1112 h
1 h = 60 min
1112 h =
1112 x 60 = 55 min
1
1112 h = 1 h 55 min
Time that Luis left City L:
1 h 55 min before 9.00 a.m. = 7.05 a.m.
(b)
Remaining distance that they had to cover to reach City M
= 414 - 138
= 276 km
Duration that Luis had to travel before reaching City M
= 276 ÷ 72
= 3
56 h
Duration that George had to travel before reaching City M
= 276 ÷ 69
= 4 h
Duration that George took to arrive later than Luis in City M
= 4 - 3
56=
16 h
Answer(s): (a) 7.05 a.m.; (b)
16 h