Olivia and Lucy started off at the same spot and ran at average speeds round a 2-km circular path. Olivia took 24 minutes to complete each round. Lucy completed each round in 25 minutes.
- How far ahead of Lucy would Olivia be after 9 minute? Express your answer in metres.
- How long would it take Olivia to meet Lucy for the first time?
- How many rounds would Olivia have completed by then?
(a)
Olivia's speed =
224 =
112 km/min
Lucy's speed =
225 km/min
Difference in speeds
=
112 -
225=
25300 -
24300=
1300 km/min
Distance between Olivia and Lucy after 9 min
= 9 x
1300=
9300 km
1 km = 1000 m
9300 km =
9300 x 1000 = 30
(b)
LCM of 24 and 25 = 600
60 min = 1 h
600 min = 600 ÷ 60 = 10
Olivia and Lucy will meet for the first time after 10 h.
(c)
Rounds Olivia completed
= 600 ÷ 24
= 25
Answer(s): (a) 30 m; (b) 10 h; (c) 25