Diana and Vanessa started off at the same spot and ran at average speeds round a 5-km circular path. Diana took 20 minutes to complete each round. Vanessa completed each round in 24 minutes.
- How far ahead of Vanessa would Diana be after 6 minute? Express your answer in metres.
- How long would it take Diana to meet Vanessa for the first time?
- How many rounds would Diana have completed by then?
(a)
Diana's speed =
520 =
14 km/min
Vanessa's speed =
524 km/min
Difference in speeds
=
14 -
524=
624 -
524=
124 km/min
Distance between Diana and Vanessa after 6 min
= 6 x
124=
624 km
1 km = 1000 m
624 km =
624 x 1000 = 250
(b)
LCM of 20 and 24 = 120
60 min = 1 h
120 min = 120 ÷ 60 = 2
Diana and Vanessa will meet for the first time after 2 h.
(c)
Rounds Diana completed
= 120 ÷ 20
= 6
Answer(s): (a) 250 m; (b) 2 h; (c) 6