Raeann and Ivan started off from the same place and drove at uniform speeds in the same direction round a 40 km circular racing track. Raeann completed each round in 40 minutes. Ivan took 80 minutes to complete each round.
- How far would Ivan be behind Raeann after 1 hour?
- How long after they started would it take Raeann to meet Ivan 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
80 min =
8060 h = 1
13 h
Raeann's speed
= 40 ÷
23= 40 x
32= 60 km/h
Ivan's speed
= 40 ÷ 1
13= 40 x
34= 30 km/h
Distance between Raeann and Ivan after 1 hour
= 60 - 30
= 30 km
(b)
LCM of 40 and 80 = 80
80 min =
8060 h = 1
13 h
Time needed for Raeann to meet Ivan for the first time = 1
13 h
Answer(s): (a) 30 km; (b) 1
13 h