City J and City K is 468 km apart. Julian left City J for City K at 7.00 a.m. travelling at an average speed of 78 km/h. Zeph left City J later than Julian and caught up with him at 10.00 a.m. Zeph was travelling at a speed of 108 km/h.
- At what time did Zeph leave City J?
- How much later did Julian arrive in City K than Zeph? 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 Julian covered when Zeph caught up with Julian
= 3 x 78
= 234 km
Time that Zeph took to travel 234 km
= 234 ÷ 108
= 2
16 h
1 h = 60 min
16 h =
16 x 60 = 10 min
2
16 h = 2 h 10 min
Time that Zeph left City J:
2 h 10 min before 10.00 a.m. = 7.50 a.m.
(b)
Remaining distance that they had to cover to reach City K
= 468 - 234
= 234 km
Duration that Zeph had to travel before reaching City K
= 234 ÷ 108
= 2
16 h
Duration that Julian had to travel before reaching City K
= 234 ÷ 78
= 3 h
Duration that Julian took to arrive later than Zeph in City K
= 3 - 2
16=
56 h
Answer(s): (a) 7.50 a.m.; (b)
56 h