Xylia and Usha started off at the same spot and ran at average speeds round a 5-km circular path. Xylia took 20 minutes to complete each round. Usha completed each round in 24 minutes.
- How far ahead of Usha would Xylia be after 3 minute? Express your answer in metres.
- How long would it take Xylia to meet Usha for the first time?
- How many rounds would Xylia have completed by then?
(a)
Xylia's speed =
520 =
14 km/min
Usha's speed =
524 km/min
Difference in speeds
=
14 -
524=
624 -
524=
124 km/min
Distance between Xylia and Usha after 3 min
= 3 x
124=
324 km
1 km = 1000 m
324 km =
324 x 1000 = 125
(b)
LCM of 20 and 24 = 120
60 min = 1 h
120 min = 120 ÷ 60 = 2
Xylia and Usha will meet for the first time after 2 h.
(c)
Rounds Xylia completed
= 120 ÷ 20
= 6
Answer(s): (a) 125 m; (b) 2 h; (c) 6