At 05 20, Mary left Town E and cycled towards Town F. Wendy left Town E and cycled towards Town F at 05 50. Wendy's cycling speed was 2 km/h faster than Mary. At 10 20, Wendy caught up with Mary. Find the cycling speed of each cyclist.
- Mary
- Wendy
(a)
Duration that Wendy cycled from 05 50 to 10 20
= 4
3060 = 4
12 h
Distance that Wendy cycled more than Mary
= 4
12 x 2
= 9 km
However, since Mary left 30 minutes earlier than Wendy and Wendy caught up with Mary, it means that Mary has cycled 9 km in 30 min.
1 h = 60 min
30 min = 30 ÷ 60 =
12 h
Mary's cycling speed
= 9 ÷
12 = 9 x
21 = 18 km/h
(b)
Wendy's cycling speed
= 18 + 2
= 20 km/h
Answer(s): (a) 18 km/h ; (b) 20 km/h
