At 06 25, Shiyun left Town C and cycled towards Town D. Dana left Town C and cycled towards Town D at 06 55. Dana's cycling speed was 2 km/h faster than Shiyun. At 11 25, Dana caught up with Shiyun. Find the cycling speed of each cyclist.
- Shiyun
- Dana
(a)
Duration that Dana cycled from 06 55 to 11 25
= 4
3060 = 4
12 h
Distance that Dana cycled more than Shiyun
= 4
12 x 2
= 9 km
However, since Shiyun left 30 minutes earlier than Dana and Dana caught up with Shiyun, it means that Shiyun has cycled 9 km in 30 min.
1 h = 60 min
30 min = 30 ÷ 60 =
12 h
Shiyun's cycling speed
= 9 ÷
12 = 9 x
21 = 18 km/h
(b)
Dana's cycling speed
= 18 + 2
= 20 km/h
Answer(s): (a) 18 km/h ; (b) 20 km/h
