Jean and Hilda started off at the same spot and ran at average speeds round a 6-km circular path. Jean took 12 minutes to complete each round. Hilda completed each round in 25 minutes.
- How far ahead of Hilda would Jean be after 4 minute? Express your answer in metres.
- How long would it take Jean to meet Hilda for the first time?
- How many rounds would Jean have completed by then?
(a)
Jean's speed =
612 =
12 km/min
Hilda's speed =
625 km/min
Difference in speeds
=
12 -
625=
2550 -
1250=
1350 km/min
Distance between Jean and Hilda after 4 min
= 4 x
1350= 1
250 km
1 km = 1000 m
1
250 km = 1
250 x 1000 = 1040
(b)
LCM of 12 and 25 = 300
60 min = 1 h
300 min = 300 ÷ 60 = 5
Jean and Hilda will meet for the first time after 5 h.
(c)
Rounds Jean completed
= 300 ÷ 12
= 25
Answer(s): (a) 1040 m; (b) 5 h; (c) 25