Diana and Jen started off at the same spot and ran at average speeds round a 3-km circular path. Diana took 12 minutes to complete each round. Jen completed each round in 25 minutes.
- How far ahead of Jen would Diana be after 10 minute? Express your answer in metres.
- How long would it take Diana to meet Jen for the first time?
- How many rounds would Diana have completed by then?
(a)
Diana's speed =
312 =
14 km/min
Jen's speed =
325 km/min
Difference in speeds
=
14 -
325=
25100 -
12100=
13100 km/min
Distance between Diana and Jen after 10 min
= 10 x
13100= 1
30100 km
1 km = 1000 m
1
30100 km = 1
30100 x 1000 = 1300
(b)
LCM of 12 and 25 = 300
60 min = 1 h
300 min = 300 ÷ 60 = 5
Diana and Jen will meet for the first time after 5 h.
(c)
Rounds Diana completed
= 300 ÷ 12
= 25
Answer(s): (a) 1300 m; (b) 5 h; (c) 25