Tina and Nora started off at the same spot and ran at average speeds round a 4-km circular path. Tina took 24 minutes to complete each round. Nora completed each round in 25 minutes.
- How far ahead of Nora would Tina be after 9 minute? Express your answer in metres.
- How long would it take Tina to meet Nora for the first time?
- How many rounds would Tina have completed by then?
(a)
Tina's speed =
424 =
16 km/min
Nora's speed =
425 km/min
Difference in speeds
=
16 -
425=
25150 -
24150=
1150 km/min
Distance between Tina and Nora after 9 min
= 9 x
1150=
9150 km
1 km = 1000 m
9150 km =
9150 x 1000 = 60
(b)
LCM of 24 and 25 = 600
60 min = 1 h
600 min = 600 ÷ 60 = 10
Tina and Nora will meet for the first time after 10 h.
(c)
Rounds Tina completed
= 600 ÷ 24
= 25
Answer(s): (a) 60 m; (b) 10 h; (c) 25