Wendy and Valen started off from the same place and drove at uniform speeds in the same direction round a 30 km circular racing track. Wendy completed each round in 40 minutes. Valen took 90 minutes to complete each round.
- How far would Valen be behind Wendy after 1 hour?
- How long after they started would it take Wendy to meet Valen for the first time? Express your answer as a whole or mixed number in h.
(a)
60 min = 1 h
1 min =
160 h
40 min =
4060 h =
23 h
90 min =
9060 h = 1
12 h
Wendy's speed
= 30 ÷
23= 30 x
32= 45 km/h
Valen's speed
= 30 ÷ 1
12= 30 x
23= 20 km/h
Distance between Wendy and Valen after 1 hour
= 45 - 20
= 25 km
(b)
LCM of 40 and 90 = 360
360 min =
36060 h = 6 h
Time needed for Wendy to meet Valen for the first time = 6 h
Answer(s): (a) 25 km; (b) 6 h