At 09 25, Dana left Town C and cycled towards Town D. Risa left Town C and cycled towards Town D at 09 55. Risa's cycling speed was 2 km/h faster than Dana. At 11 25, Risa caught up with Dana. Find the cycling speed of each cyclist.
- Dana
- Risa
(a)
Duration that Risa cycled from 09 55 to 11 25
= 1
3060 = 1
12 h
Distance that Risa cycled more than Dana
= 1
12 x 2
= 3 km
However, since Dana left 30 minutes earlier than Risa and Risa caught up with Dana, it means that Dana has cycled 3 km in 30 min.
1 h = 60 min
30 min = 30 ÷ 60 =
12 h
Dana's cycling speed
= 3 ÷
12 = 3 x
21 = 6 km/h
(b)
Risa's cycling speed
= 6 + 2
= 8 km/h
Answer(s): (a) 6 km/h ; (b) 8 km/h
