Olivia and Lynn started off at the same spot and ran at average speeds round a 3-km circular path. Olivia took 18 minutes to complete each round. Lynn completed each round in 20 minutes.
- How far ahead of Lynn would Olivia be after 3 minute? Express your answer in metres.
- How long would it take Olivia to meet Lynn for the first time?
- How many rounds would Olivia have completed by then?
(a)
Olivia's speed =
318 =
16 km/min
Lynn's speed =
320 km/min
Difference in speeds
=
16 -
320=
1060 -
960=
160 km/min
Distance between Olivia and Lynn after 3 min
= 3 x
160=
360 km
1 km = 1000 m
360 km =
360 x 1000 = 50
(b)
LCM of 18 and 20 = 180
60 min = 1 h
180 min = 180 ÷ 60 = 3
Olivia and Lynn will meet for the first time after 3 h.
(c)
Rounds Olivia completed
= 180 ÷ 18
= 10
Answer(s): (a) 50 m; (b) 3 h; (c) 10