Yen and Sabrina started off at the same spot and ran at average speeds round a 4-km circular path. Yen took 24 minutes to complete each round. Sabrina completed each round in 30 minutes.
- How far ahead of Sabrina would Yen be after 6 minute? Express your answer in metres.
- How long would it take Yen to meet Sabrina for the first time?
- How many rounds would Yen have completed by then?
(a)
Yen's speed =
424 =
16 km/min
Sabrina's speed =
215 km/min
Difference in speeds
=
16 -
215=
530 -
430=
130 km/min
Distance between Yen and Sabrina after 6 min
= 6 x
130=
630 km
1 km = 1000 m
630 km =
630 x 1000 = 200
(b)
LCM of 24 and 30 = 120
60 min = 1 h
120 min = 120 ÷ 60 = 2
Yen and Sabrina will meet for the first time after 2 h.
(c)
Rounds Yen completed
= 120 ÷ 24
= 5
Answer(s): (a) 200 m; (b) 2 h; (c) 5