City W and City X is 539 km apart. Zeph left City W for City X at 10.00 a.m. travelling at an average speed of 77 km/h. Vaidev left City W later than Zeph and caught up with him at 1.00 p.m. Vaidev was travelling at a speed of 99 km/h.
- At what time did Vaidev leave City W?
- How much later did Zeph arrive in City X than Vaidev? Express your answer in h as a fraction or mixed number.
(a)
From 10.00 a.m. to 1.00 p.m. = 3 h
Distance that Zeph covered when Vaidev caught up with Zeph
= 3 x 77
= 231 km
Time that Vaidev took to travel 231 km
= 231 ÷ 99
= 2
13 h
1 h = 60 min
13 h =
13 x 60 = 20 min
2
13 h = 2 h 20 min
Time that Vaidev left City W:
2 h 20 min before 1.00 p.m. = 10.40 a.m.
(b)
Remaining distance that they had to cover to reach City X
= 539 - 231
= 308 km
Duration that Vaidev had to travel before reaching City X
= 308 ÷ 99
= 3
19 h
Duration that Zeph had to travel before reaching City X
= 308 ÷ 77
= 4 h
Duration that Zeph took to arrive later than Vaidev in City X
= 4 - 3
19=
89 h
Answer(s): (a) 10.40 a.m.; (b)
89 h