At 09 15, Betty left Town U and cycled towards Town V. Joelle left Town U and cycled towards Town V at 09 45. Joelle's cycling speed was 4 km/h faster than Betty. At 11 15, Joelle caught up with Betty. Find the cycling speed of each cyclist.
- Betty
- Joelle
(a)
Duration that Joelle cycled from 09 45 to 11 15
= 1
3060 = 1
12 h
Distance that Joelle cycled more than Betty
= 1
12 x 4
= 6 km
However, since Betty left 30 minutes earlier than Joelle and Joelle caught up with Betty, it means that Betty has cycled 6 km in 30 min.
1 h = 60 min
30 min = 30 ÷ 60 =
12 h
Betty's cycling speed
= 6 ÷
12 = 6 x
21 = 12 km/h
(b)
Joelle's cycling speed
= 12 + 4
= 16 km/h
Answer(s): (a) 12 km/h ; (b) 16 km/h
