City Y and City Z is 390 km apart. Tommy left City Y for City Z at 7.00 a.m. travelling at an average speed of 78 km/h. George left City Y later than Tommy and caught up with him at 10.00 a.m. George was travelling at a speed of 104 km/h.
- At what time did George leave City Y?
- How much later did Tommy arrive in City Z than George? 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 Tommy covered when George caught up with Tommy
= 3 x 78
= 234 km
Time that George took to travel 234 km
= 234 ÷ 104
= 2
14 h
1 h = 60 min
14 h =
14 x 60 = 15 min
2
14 h = 2 h 15 min
Time that George left City Y:
2 h 15 min before 10.00 a.m. = 7.45 a.m.
(b)
Remaining distance that they had to cover to reach City Z
= 390 - 234
= 156 km
Duration that George had to travel before reaching City Z
= 156 ÷ 104
= 1
12 h
Duration that Tommy had to travel before reaching City Z
= 156 ÷ 78
= 2 h
Duration that Tommy took to arrive later than George in City Z
= 2 - 1
12=
12 h
Answer(s): (a) 7.45 a.m.; (b)
12 h
