Roshel and Fred started off from the same place and drove at uniform speeds in the same direction round a 60 km circular racing track. Roshel completed each round in 50 minutes. Fred took 100 minutes to complete each round.
- How far would Fred be behind Roshel after 1 hour?
- How long after they started would it take Roshel to meet Fred 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
100 min =
10060 h = 1
23 h
Roshel's speed
= 60 ÷
56= 60 x
65= 72 km/h
Fred's speed
= 60 ÷ 1
23= 60 x
35= 36 km/h
Distance between Roshel and Fred after 1 hour
= 72 - 36
= 36 km
(b)
LCM of 50 and 100 = 100
100 min =
10060 h = 1
23 h
Time needed for Roshel to meet Fred for the first time = 1
23 h
Answer(s): (a) 36 km; (b) 1
23 h