City X and City Y is 375 km apart. Ivan left City X for City Y at 8.00 a.m. travelling at an average speed of 75 km/h. Pierre left City X later than Ivan and caught up with him at 10.00 a.m. Pierre was travelling at a speed of 90 km/h.
- At what time did Pierre leave City X?
- How much later did Ivan arrive in City Y than Pierre? 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 Ivan covered when Pierre caught up with Ivan
= 2 x 75
= 150 km
Time that Pierre took to travel 150 km
= 150 ÷ 90
= 1
23 h
1 h = 60 min
23 h =
23 x 60 = 40 min
1
23 h = 1 h 40 min
Time that Pierre left City X:
1 h 40 min before 10.00 a.m. = 8.20 a.m.
(b)
Remaining distance that they had to cover to reach City Y
= 375 - 150
= 225 km
Duration that Pierre had to travel before reaching City Y
= 225 ÷ 90
= 2
12 h
Duration that Ivan had to travel before reaching City Y
= 225 ÷ 75
= 3 h
Duration that Ivan took to arrive later than Pierre in City Y
= 3 - 2
12=
12 h
Answer(s): (a) 8.20 a.m.; (b)
12 h