Elyse and Ian started off from the same place and drove at uniform speeds in the same direction round a 25 km circular racing track. Elyse completed each round in 50 minutes. Ian took 100 minutes to complete each round.
- How far would Ian be behind Elyse after 1 hour?
- How long after they started would it take Elyse to meet Ian for the first time? Express your answer as a whole or mixed number in h.
(a)
60 min = 1 h
1 min =
160 h
50 min =
5060 h =
56 h
100 min =
10060 h = 1
23 h
Elyse's speed
= 25 ÷
56= 25 x
65= 30 km/h
Ian's speed
= 25 ÷ 1
23= 25 x
35= 15 km/h
Distance between Elyse and Ian after 1 hour
= 30 - 15
= 15 km
(b)
LCM of 50 and 100 = 100
100 min =
10060 h = 1
23 h
Time needed for Elyse to meet Ian for the first time = 1
23 h
Answer(s): (a) 15 km; (b) 1
23 h