Jean and Eric started off from the same place and drove at uniform speeds in the same direction round a 50 km circular racing track. Jean completed each round in 40 minutes. Eric took 50 minutes to complete each round.
- How far would Eric be behind Jean after 1 hour?
- How long after they started would it take Jean to meet Eric 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
Jean's speed
= 50 ÷
23= 50 x
32= 75 km/h
Eric's speed
= 50 ÷
56= 50 x
65= 60 km/h
Distance between Jean and Eric after 1 hour
= 75 - 60
= 15 km
(b)
LCM of 40 and 50 = 200
200 min =
20060 h = 3
13 h
Time needed for Jean to meet Eric for the first time = 3
13 h
Answer(s): (a) 15 km; (b) 3
13 h