At 07 15, Rachel left Town W and cycled towards Town X. Gwen left Town W and cycled towards Town X at 07 45. Gwen's cycling speed was 4 km/h faster than Rachel. At 10 15, Gwen caught up with Rachel. Find the cycling speed of each cyclist.
- Rachel
- Gwen
(a)
Duration that Gwen cycled from 07 45 to 10 15
= 2
3060 = 2
12 h
Distance that Gwen cycled more than Rachel
= 2
12 x 4
= 10 km
However, since Rachel left 30 minutes earlier than Gwen and Gwen caught up with Rachel, it means that Rachel has cycled 10 km in 30 min.
1 h = 60 min
30 min = 30 ÷ 60 =
12 h
Rachel's cycling speed
= 10 ÷
12 = 10 x
21 = 20 km/h
(b)
Gwen's cycling speed
= 20 + 4
= 24 km/h
Answer(s): (a) 20 km/h ; (b) 24 km/h
