Cindy and Ben started off from the same place and drove at uniform speeds in the same direction round a 35 km circular racing track. Cindy completed each round in 50 minutes. Ben took 70 minutes to complete each round.
- How far would Ben be behind Cindy after 1 hour?
- How long after they started would it take Cindy to meet Ben for the first time? Express your answer as a whole or mixed number in h.
(a)
60 min = 1 h
1 min =
160 h
50 min =
5060 h =
56 h
70 min =
7060 h = 1
16 h
Cindy's speed
= 35 ÷
56= 35 x
65= 42 km/h
Ben's speed
= 35 ÷ 1
16= 35 x
67= 30 km/h
Distance between Cindy and Ben after 1 hour
= 42 - 30
= 12 km
(b)
LCM of 50 and 70 = 350
350 min =
35060 h = 5
56 h
Time needed for Cindy to meet Ben for the first time = 5
56 h
Answer(s): (a) 12 km; (b) 5
56 h