At 09 20, Barbara left Town W and cycled towards Town X. Ivory left Town W and cycled towards Town X at 09 50. Ivory's cycling speed was 6 km/h faster than Barbara. At 11 20, Ivory caught up with Barbara. Find the cycling speed of each cyclist.

1. Barbara
2. Ivory

(a)
Duration that Ivory cycled from 09 50 to 11 20
= 1³⁰₆₀
= 1¹₂ h

Distance that Ivory cycled more than Barbara
= 1¹₂ x 6
= 9 km

However, since Barbara left 30 minutes earlier than Ivory and Ivory caught up with Barbara, it means that Barbara has cycled 9 km in 30 min.

1 h = 60 min 
30 min = 30 ÷ 60 = ¹₂ h

Barbara's cycling speed
= 9 ÷ ¹₂
= 9 x ²₁
= 18 km/h

(b)
Ivory's cycling speed
= 18 + 6
= 24 km/h

Answer(s): (a) 18 km/h ; (b) 24 km/h