Kimberly and Elyse started off at the same spot and ran at average speeds round a 3-km circular path. Kimberly took 12 minutes to complete each round. Elyse completed each round in 25 minutes.
- How far ahead of Elyse would Kimberly be after 7 minute? Express your answer in metres.
- How long would it take Kimberly to meet Elyse for the first time?
- How many rounds would Kimberly have completed by then?
(a)
Kimberly's speed =
312 =
14 km/min
Elyse's speed =
325 km/min
Difference in speeds
=
14 -
325=
25100 -
12100=
13100 km/min
Distance between Kimberly and Elyse after 7 min
= 7 x
13100=
91100 km
1 km = 1000 m
91100 km =
91100 x 1000 = 910
(b)
LCM of 12 and 25 = 300
60 min = 1 h
300 min = 300 ÷ 60 = 5
Kimberly and Elyse will meet for the first time after 5 h.
(c)
Rounds Kimberly completed
= 300 ÷ 12
= 25
Answer(s): (a) 910 m; (b) 5 h; (c) 25