At 7.00 p.m., a brown car and a red car left the office and travelled at average speeds in opposite directions round a 35-km route. The brown car took 15 minutes to complete each round while the red car took 30 minutes.
- Find the speed of the brown car.
- Find the speed of the red 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 brown car
= 35 ÷
14= 35 x
41= 140 km/h
(b)
Speed of the red car
= 35 ÷
12= 35 x
21= 70 km/h
(c)
LCM of 15 and 30 = 30
30 min after 7 p.m. = 7.30 p.m.
Time that the two cars would meet again at the office = 7.30 p.m.
Answer(s): (a) 140 km/h; (b) 70 km/h; (c) 7.30 p.m.