Usha and Jenson started off from the same place and drove at uniform speeds in the same direction round a 35 km circular racing track. Usha completed each round in 50 minutes. Jenson took 60 minutes to complete each round.
- How far would Jenson be behind Usha after 1 hour?
- How long after they started would it take Usha to meet Jenson 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
60 min =
6060 h = 1 h
Usha's speed
= 35 ÷
56= 35 x
65= 42 km/h
Jenson's speed
= 35 ÷ 1
= 35 x
11= 35 km/h
Distance between Usha and Jenson after 1 hour
= 42 - 35
= 7 km
(b)
LCM of 50 and 60 = 300
300 min =
30060 h = 5 h
Time needed for Usha to meet Jenson for the first time = 5 h
Answer(s): (a) 7 km; (b) 5 h