Raeann and Andy started off from the same place and drove at uniform speeds in the same direction round a 50 km circular racing track. Raeann completed each round in 40 minutes. Andy took 60 minutes to complete each round.
- How far would Andy be behind Raeann after 1 hour?
- How long after they started would it take Raeann to meet Andy for the first time? Express your answer as a whole or mixed number in h.
(a)
60 min = 1 h
1 min =
160 h
40 min =
4060 h =
23 h
60 min =
6060 h = 1 h
Raeann's speed
= 50 ÷
23= 50 x
32= 75 km/h
Andy's speed
= 50 ÷ 1
= 50 x
11= 50 km/h
Distance between Raeann and Andy after 1 hour
= 75 - 50
= 25 km
(b)
LCM of 40 and 60 = 120
120 min =
12060 h = 2 h
Time needed for Raeann to meet Andy for the first time = 2 h
Answer(s): (a) 25 km; (b) 2 h