At 6.00 p.m., a brown car and a red car left the office and travelled at average speeds in opposite directions round a 40-km route. The brown car took 15 minutes to complete each round while the red car took 25 minutes.
- Find the speed of the brown car.
- Find the speed of the red car.
- If the 2 cars travelled without any interval of rest, at what time would the 2 cars next meet again at the office?
(a)
60 min = 1 h
15 min =
1560 =
14 h
25 min =
2560 =
512 h
Speed of the brown car
= 40 ÷
14= 40 x
41= 160 km/h
(b)
Speed of the red car
= 40 ÷
512= 40 x
125= 96 km/h
(c)
LCM of 15 and 25 = 75
1 hr = 60 min
75 min = 1 h 15 min
1 h and 15 min after 6 p.m. = 7.15 p.m.
Time that the two cars would meet again at the office = 7.15 p.m.
Answer(s): (a) 160 km/h; (b) 96 km/h; (c) 7.15 p.m.