At 08 20, Julie left Town U and cycled towards Town V. Risa left Town U and cycled towards Town V at 08 50. Risa's cycling speed was 6 km/h faster than Julie. At 11 20, Risa caught up with Julie. Find the cycling speed of each cyclist.
- Julie
- Risa
(a)
Duration that Risa cycled from 08 50 to 11 20
= 2
3060 = 2
12 h
Distance that Risa cycled more than Julie
= 2
12 x 6
= 15 km
However, since Julie left 30 minutes earlier than Risa and Risa caught up with Julie, it means that Julie has cycled 15 km in 30 min.
1 h = 60 min
30 min = 30 ÷ 60 =
12 h
Julie's cycling speed
= 15 ÷
12 = 15 x
21 = 30 km/h
(b)
Risa's cycling speed
= 30 + 6
= 36 km/h
Answer(s): (a) 30 km/h ; (b) 36 km/h
