Gwen and Tim started off from the same place and drove at uniform speeds in the same direction round a 60 km circular racing track. Gwen completed each round in 40 minutes. Tim took 50 minutes to complete each round.
- How far would Tim be behind Gwen after 1 hour?
- How long after they started would it take Gwen to meet Tim 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
50 min =
5060 h =
56 h
Gwen's speed
= 60 ÷
23= 60 x
32= 90 km/h
Tim's speed
= 60 ÷
56= 60 x
65= 72 km/h
Distance between Gwen and Tim after 1 hour
= 90 - 72
= 18 km
(b)
LCM of 40 and 50 = 200
200 min =
20060 h = 3
13 h
Time needed for Gwen to meet Tim for the first time = 3
13 h
Answer(s): (a) 18 km; (b) 3
13 h