Erika and Brandon started off from the same place and drove at uniform speeds in the same direction round a 60 km circular racing track. Erika completed each round in 40 minutes. Brandon took 60 minutes to complete each round.
- How far would Brandon be behind Erika after 1 hour?
- How long after they started would it take Erika to meet Brandon 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
Erika's speed
= 60 ÷
23= 60 x
32= 90 km/h
Brandon's speed
= 60 ÷ 1
= 60 x
11= 60 km/h
Distance between Erika and Brandon after 1 hour
= 90 - 60
= 30 km
(b)
LCM of 40 and 60 = 120
120 min =
12060 h = 2 h
Time needed for Erika to meet Brandon for the first time = 2 h
Answer(s): (a) 30 km; (b) 2 h