Jane and Ivan started off from the same place and drove at uniform speeds in the same direction round a 50 km circular racing track. Jane completed each round in 40 minutes. Ivan took 100 minutes to complete each round.
- How far would Ivan be behind Jane after 1 hour?
- How long after they started would it take Jane 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
100 min =
10060 h = 1
23 h
Jane's speed
= 50 ÷
23= 50 x
32= 75 km/h
Ivan's speed
= 50 ÷ 1
23= 50 x
35= 30 km/h
Distance between Jane and Ivan after 1 hour
= 75 - 30
= 45 km
(b)
LCM of 40 and 100 = 200
200 min =
20060 h = 3
13 h
Time needed for Jane to meet Ivan for the first time = 3
13 h
Answer(s): (a) 45 km; (b) 3
13 h