At 6.00 p.m., a gold car and a green car left the office and travelled at average speeds in opposite directions round a 30-km route. The gold car took 15 minutes to complete each round while the green car took 30 minutes.
- Find the speed of the gold car.
- Find the speed of the green car.
- If the two cars travelled without any interval of rest, at what time would the two cars next meet again at the office?
(a)
60 min = 1 h
15 min =
1560 =
14 h
30 min =
3060 =
12 h
Speed of the gold car
= 30 ÷
14= 30 x
41= 120 km/h
(b)
Speed of the green car
= 30 ÷
12= 30 x
21= 60 km/h
(c)
LCM of 15 and 30 = 30
30 min after 6 p.m. = 6.30 p.m.
Time that the two cars would meet again at the office = 6.30 p.m.
Answer(s): (a) 120 km/h; (b) 60 km/h; (c) 6.30 p.m.