Diana and Abi started off at the same spot and ran at average speeds round a 2-km circular path. Diana took 20 minutes to complete each round. Abi completed each round in 30 minutes.
- How far ahead of Abi would Diana be after 6 minute? Express your answer in metres.
- How long would it take Diana to meet Abi for the first time?
- How many rounds would Diana have completed by then?
(a)
Diana's speed =
220 =
110 km/min
Abi's speed =
115 km/min
Difference in speeds
=
110 -
115=
330 -
230=
130 km/min
Distance between Diana and Abi after 6 min
= 6 x
130=
630 km
1 km = 1000 m
630 km =
630 x 1000 = 200
(b)
LCM of 20 and 30 = 60
60 min = 1 h
60 min = 60 ÷ 60 = 1
Diana and Abi will meet for the first time after 1 h.
(c)
Rounds Diana completed
= 60 ÷ 20
= 3
Answer(s): (a) 200 m; (b) 1 h; (c) 3