At 06 10, Emily left Town X and cycled towards Town Y. Risa left Town X and cycled towards Town Y at 06 40. Risa's cycling speed was 2 km/h faster than Emily. At 15 10, Risa caught up with Emily. Find the cycling speed of each cyclist.
- Emily
- Risa
(a)
Duration that Risa cycled from 06 40 to 15 10
= 8
3060 = 8
12 h
Distance that Risa cycled more than Emily
= 8
12 x 2
= 17 km
However, since Emily left 30 minutes earlier than Risa and Risa caught up with Emily, it means that Emily has cycled 17 km in 30 min.
1 h = 60 min
30 min = 30 ÷ 60 =
12 h
Emily's cycling speed
= 17 ÷
12 = 17 x
21 = 34 km/h
(b)
Risa's cycling speed
= 34 + 2
= 36 km/h
Answer(s): (a) 34 km/h ; (b) 36 km/h
