City Y and City Z is 276 km apart. Michael left City Y for City Z at 8.00 a.m. travelling at an average speed of 69 km/h. Billy left City Y later than Michael and caught up with him at 10.00 a.m. Billy was travelling at a speed of 92 km/h.
- At what time did Billy leave City Y?
- How much later did Michael arrive in City Z than Billy? 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 Michael covered when Billy caught up with Michael
= 2 x 69
= 138 km
Time that Billy took to travel 138 km
= 138 ÷ 92
= 1
12 h
1 h = 60 min
12 h =
12 x 60 = 30 min
1
12 h = 1 h 30 min
Time that Billy left City Y:
1 h 30 min before 10.00 a.m. = 8.30 a.m.
(b)
Remaining distance that they had to cover to reach City Z
= 276 - 138
= 138 km
Duration that Billy had to travel before reaching City Z
= 138 ÷ 92
= 1
12 h
Duration that Michael had to travel before reaching City Z
= 138 ÷ 69
= 2 h
Duration that Michael took to arrive later than Billy in City Z
= 2 - 1
12=
12 h
Answer(s): (a) 8.30 a.m.; (b)
12 h