City G and City H is 330 km apart. Valen left City G for City H at 7.00 a.m. travelling at an average speed of 66 km/h. David left City G later than Valen and caught up with him at 10.00 a.m. David was travelling at a speed of 72 km/h.
- At what time did David leave City G?
- How much later did Valen arrive in City H than David? Express your answer in h as a fraction or mixed number.
(a)
From 7.00 a.m. to 10.00 a.m. = 3 h
Distance that Valen covered when David caught up with Valen
= 3 x 66
= 198 km
Time that David took to travel 198 km
= 198 ÷ 72
= 2
34 h
1 h = 60 min
34 h =
34 x 60 = 45 min
2
34 h = 2 h 45 min
Time that David left City G:
2 h 45 min before 10.00 a.m. = 7.15 a.m.
(b)
Remaining distance that they had to cover to reach City H
= 330 - 198
= 132 km
Duration that David had to travel before reaching City H
= 132 ÷ 72
= 1
56 h
Duration that Valen had to travel before reaching City H
= 132 ÷ 66
= 2 h
Duration that Valen took to arrive later than David in City H
= 2 - 1
56=
16 h
Answer(s): (a) 7.15 a.m.; (b)
16 h