At 08 20, Xylia left Town G and cycled towards Town H. Tiffany left Town G and cycled towards Town H at 08 50. Tiffany's cycling speed was 4 km/h faster than Xylia. At 13 20, Tiffany caught up with Xylia. Find the cycling speed of each cyclist.

1. Xylia
2. Tiffany

(a)
Duration that Tiffany cycled from 08 50 to 13 20
= 4³⁰₆₀
= 4¹₂ h

Distance that Tiffany cycled more than Xylia
= 4¹₂ x 4
= 18 km

However, since Xylia left 30 minutes earlier than Tiffany and Tiffany caught up with Xylia, it means that Xylia has cycled 18 km in 30 min.

1 h = 60 min 
30 min = 30 ÷ 60 = ¹₂ h

Xylia's cycling speed
= 18 ÷ ¹₂
= 18 x ²₁
= 36 km/h

(b)
Tiffany's cycling speed
= 36 + 4
= 40 km/h

Answer(s): (a) 36 km/h ; (b) 40 km/h