Lucy and Jenson started off from the same place and drove at uniform speeds in the same direction round a 40 km circular racing track. Lucy completed each round in 40 minutes. Jenson took 60 minutes to complete each round.
- How far would Jenson be behind Lucy after 1 hour?
- How long after they started would it take Lucy to meet Jenson 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
60 min =
6060 h = 1 h
Lucy's speed
= 40 ÷
23= 40 x
32= 60 km/h
Jenson's speed
= 40 ÷ 1
= 40 x
11= 40 km/h
Distance between Lucy and Jenson after 1 hour
= 60 - 40
= 20 km
(b)
LCM of 40 and 60 = 120
120 min =
12060 h = 2 h
Time needed for Lucy to meet Jenson for the first time = 2 h
Answer(s): (a) 20 km; (b) 2 h