City W and City X is 360 km apart. Pierre left City W for City X at 8.00 a.m. travelling at an average speed of 60 km/h. Elijah left City W later than Pierre and caught up with him at 10.00 a.m. Elijah was travelling at a speed of 80 km/h.
- At what time did Elijah leave City W?
- How much later did Pierre arrive in City X than Elijah? Express your answer in h as a fraction or mixed number.
(a)
From 8.00 a.m. to 10.00 a.m. = 2 h
Distance that Pierre covered when Elijah caught up with Pierre
= 2 x 60
= 120 km
Time that Elijah took to travel 120 km
= 120 ÷ 80
= 1
12 h
1 h = 60 min
12 h =
12 x 60 = 30 min
1
12 h = 1 h 30 min
Time that Elijah left City W:
1 h 30 min before 10.00 a.m. = 8.30 a.m.
(b)
Remaining distance that they had to cover to reach City X
= 360 - 120
= 240 km
Duration that Elijah had to travel before reaching City X
= 240 ÷ 80
= 3 h
Duration that Pierre had to travel before reaching City X
= 240 ÷ 60
= 4 h
Duration that Pierre took to arrive later than Elijah in City X
= 4 - 3
= 1 h
Answer(s): (a) 8.30 a.m.; (b) 1 h