City F and City G is 420 km apart. Jack left City F for City G at 11.00 a.m. travelling at an average speed of 60 km/h. Zane left City F later than Jack and caught up with him at 2.00 p.m. Zane was travelling at a speed of 80 km/h.
- At what time did Zane leave City F?
- How much later did Jack arrive in City G than Zane? Express your answer in h as a fraction or mixed number.
(a)
From 11.00 a.m. to 2.00 p.m. = 3 h
Distance that Jack covered when Zane caught up with Jack
= 3 x 60
= 180 km
Time that Zane took to travel 180 km
= 180 ÷ 80
= 2
14 h
1 h = 60 min
14 h =
14 x 60 = 15 min
2
14 h = 2 h 15 min
Time that Zane left City F:
2 h 15 min before 2.00 p.m. = 11.45 a.m.
(b)
Remaining distance that they had to cover to reach City G
= 420 - 180
= 240 km
Duration that Zane had to travel before reaching City G
= 240 ÷ 80
= 3 h
Duration that Jack had to travel before reaching City G
= 240 ÷ 60
= 4 h
Duration that Jack took to arrive later than Zane in City G
= 4 - 3
= 1 h
Answer(s): (a) 11.45 a.m.; (b) 1 h