Gillian and Joelle started off at the same spot and ran at average speeds round a 2-km circular path. Gillian took 24 minutes to complete each round. Joelle completed each round in 30 minutes.
- How far ahead of Joelle would Gillian be after 9 minute? Express your answer in metres.
- How long would it take Gillian to meet Joelle for the first time?
- How many rounds would Gillian have completed by then?
(a)
Gillian's speed =
224 =
112 km/min
Joelle's speed =
115 km/min
Difference in speeds
=
112 -
115=
560 -
460=
160 km/min
Distance between Gillian and Joelle after 9 min
= 9 x
160=
960 km
1 km = 1000 m
960 km =
960 x 1000 = 150
(b)
LCM of 24 and 30 = 120
60 min = 1 h
120 min = 120 ÷ 60 = 2
Gillian and Joelle will meet for the first time after 2 h.
(c)
Rounds Gillian completed
= 120 ÷ 24
= 5
Answer(s): (a) 150 m; (b) 2 h; (c) 5