At 05 15, Betty left Town W and cycled towards Town X. Diana left Town W and cycled towards Town X at 05 45. Diana's cycling speed was 2 km/h faster than Betty. At 11 15, Diana caught up with Betty. Find the cycling speed of each cyclist.
- Betty
- Diana
(a)
Duration that Diana cycled from 05 45 to 11 15
= 5
3060 = 5
12 h
Distance that Diana cycled more than Betty
= 5
12 x 2
= 11 km
However, since Betty left 30 minutes earlier than Diana and Diana caught up with Betty, it means that Betty has cycled 11 km in 30 min.
1 h = 60 min
30 min = 30 ÷ 60 =
12 h
Betty's cycling speed
= 11 ÷
12 = 11 x
21 = 22 km/h
(b)
Diana's cycling speed
= 22 + 2
= 24 km/h
Answer(s): (a) 22 km/h ; (b) 24 km/h
