City N and City P is 504 km apart. John left City N for City P at 7.00 a.m. travelling at an average speed of 72 km/h. Ian left City N later than John and caught up with him at 9.00 a.m. Ian was travelling at a speed of 108 km/h.
- At what time did Ian leave City N?
- How much later did John arrive in City P than Ian? Express your answer in h as a fraction or mixed number.
(a)
From 7.00 a.m. to 9.00 a.m. = 2 h
Distance that John covered when Ian caught up with John
= 2 x 72
= 144 km
Time that Ian took to travel 144 km
= 144 ÷ 108
= 1
13 h
1 h = 60 min
13 h =
13 x 60 = 20 min
1
13 h = 1 h 20 min
Time that Ian left City N:
1 h 20 min before 9.00 a.m. = 7.40 a.m.
(b)
Remaining distance that they had to cover to reach City P
= 504 - 144
= 360 km
Duration that Ian had to travel before reaching City P
= 360 ÷ 108
= 3
13 h
Duration that John had to travel before reaching City P
= 360 ÷ 72
= 5 h
Duration that John took to arrive later than Ian in City P
= 5 - 3
13= 1
23 h
Answer(s): (a) 7.40 a.m.; (b) 1
23 h
