At 07 15, Risa left Town R and cycled towards Town S. Nicole left Town R and cycled towards Town S at 07 45. Nicole's cycling speed was 6 km/h faster than Risa. At 10 15, Nicole caught up with Risa. Find the cycling speed of each cyclist.
- Risa
- Nicole
(a)
Duration that Nicole cycled from 07 45 to 10 15
= 2
3060 = 2
12 h
Distance that Nicole cycled more than Risa
= 2
12 x 6
= 15 km
However, since Risa left 30 minutes earlier than Nicole and Nicole caught up with Risa, it means that Risa has cycled 15 km in 30 min.
1 h = 60 min
30 min = 30 ÷ 60 =
12 h
Risa's cycling speed
= 15 ÷
12 = 15 x
21 = 30 km/h
(b)
Nicole's cycling speed
= 30 + 6
= 36 km/h
Answer(s): (a) 30 km/h ; (b) 36 km/h
