Vanessa and Gillian started off at the same spot and ran at average speeds round a 2-km circular path. Vanessa took 20 minutes to complete each round. Gillian completed each round in 30 minutes.
- How far ahead of Gillian would Vanessa be after 3 minute? Express your answer in metres.
- How long would it take Vanessa to meet Gillian for the first time?
- How many rounds would Vanessa have completed by then?
(a)
Vanessa's speed =
220 =
110 km/min
Gillian's speed =
115 km/min
Difference in speeds
=
110 -
115=
330 -
230=
130 km/min
Distance between Vanessa and Gillian after 3 min
= 3 x
130=
330 km
1 km = 1000 m
330 km =
330 x 1000 = 100
(b)
LCM of 20 and 30 = 60
60 min = 1 h
60 min = 60 ÷ 60 = 1
Vanessa and Gillian will meet for the first time after 1 h.
(c)
Rounds Vanessa completed
= 60 ÷ 20
= 3
Answer(s): (a) 100 m; (b) 1 h; (c) 3