Joelle and Ryan started off from the same place and drove at uniform speeds in the same direction round a 40 km circular racing track. Joelle completed each round in 60 minutes. Ryan took 100 minutes to complete each round.
- How far would Ryan be behind Joelle after 1 hour?
- How long after they started would it take Joelle to meet Ryan for the first time? Express your answer as a whole or mixed number in h.
(a)
60 min = 1 h
1 min =
160 h
60 min =
6060 h = 1 h
100 min =
10060 h = 1
23 h
Joelle's speed
= 40 ÷ 1
= 40 x
11= 40 km/h
Ryan's speed
= 40 ÷ 1
23= 40 x
35= 24 km/h
Distance between Joelle and Ryan after 1 hour
= 40 - 24
= 16 km
(b)
LCM of 60 and 100 = 300
300 min =
30060 h = 5 h
Time needed for Joelle to meet Ryan for the first time = 5 h
Answer(s): (a) 16 km; (b) 5 h