Elyse and Andy started off from the same place and drove at uniform speeds in the same direction round a 40 km circular racing track. Elyse completed each round in 50 minutes. Andy took 60 minutes to complete each round.
- How far would Andy be behind Elyse after 1 hour?
- How long after they started would it take Elyse 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
50 min =
5060 h =
56 h
60 min =
6060 h = 1 h
Elyse's speed
= 40 ÷
56= 40 x
65= 48 km/h
Andy's speed
= 40 ÷ 1
= 40 x
11= 40 km/h
Distance between Elyse and Andy after 1 hour
= 48 - 40
= 8 km
(b)
LCM of 50 and 60 = 300
300 min =
30060 h = 5 h
Time needed for Elyse to meet Andy for the first time = 5 h
Answer(s): (a) 8 km; (b) 5 h