Shiyun and Hazel started off at the same spot and ran at average speeds round a 4-km circular path. Shiyun took 16 minutes to complete each round. Hazel completed each round in 30 minutes.
- How far ahead of Hazel would Shiyun be after 6 minute? Express your answer in metres.
- How long would it take Shiyun to meet Hazel for the first time?
- How many rounds would Shiyun have completed by then?
(a)
Shiyun's speed =
416 =
14 km/min
Hazel's speed =
215 km/min
Difference in speeds
=
14 -
215=
1560 -
860=
760 km/min
Distance between Shiyun and Hazel after 6 min
= 6 x
760=
4260 km
1 km = 1000 m
4260 km =
4260 x 1000 = 700
(b)
LCM of 16 and 30 = 240
60 min = 1 h
240 min = 240 ÷ 60 = 4
Shiyun and Hazel will meet for the first time after 4 h.
(c)
Rounds Shiyun completed
= 240 ÷ 16
= 15
Answer(s): (a) 700 m; (b) 4 h; (c) 15