Gem and Elyse started off at the same spot and ran at average speeds round a 4-km circular path. Gem took 12 minutes to complete each round. Elyse completed each round in 25 minutes.
- How far ahead of Elyse would Gem be after 9 minute? Express your answer in metres.
- How long would it take Gem to meet Elyse for the first time?
- How many rounds would Gem have completed by then?
(a)
Gem's speed =
412 =
13 km/min
Elyse's speed =
425 km/min
Difference in speeds
=
13 -
425=
2575 -
1275=
1375 km/min
Distance between Gem and Elyse after 9 min
= 9 x
1375= 1
4275 km
1 km = 1000 m
1
4275 km = 1
4275 x 1000 = 1560
(b)
LCM of 12 and 25 = 300
60 min = 1 h
300 min = 300 ÷ 60 = 5
Gem and Elyse will meet for the first time after 5 h.
(c)
Rounds Gem completed
= 300 ÷ 12
= 25
Answer(s): (a) 1560 m; (b) 5 h; (c) 25