The distance between Town L and Town M was 166 km. At 05 00, Risa left Town L and cycled towards Town M. Winnie left Town L and cycled towards Town M at 05 40. Winnie's cycling speed was 3 km/h faster than Risa. At 10 00, Winnie caught up with Risa. When Winnie was 22 km from Town M, she stopped to wait for Risa. How far was Risa from Winnie when she stopped to wait for him?
Duration in which Winnie cycled for before she caught up with Risa
= from 05 40 to 10 00
= 4 h 20 min
= 4 ²⁰₆₀ h
= 4 ¹₃ h

Distance that Winnie cycled more than Risa
= 4¹₃ x 3
= ¹³₃ x 3
= 5 km

Risa's cycling speed
= 5 x 3
= 15 km/h

Winnie's cycling speed
= 15 + 3
= 18 km/h

Distance that Winnie cycled before she stopped to wait for Risa
= 166 - 22
= 144 km

Duration that Winnie cycled for after she caught up with Risa and when she stopped to wait for Risa
= (144 ÷ 18) - 4¹₃
= 8 - 4¹₃
= 3²₃ h

Distance Risa was from Winnie when she stopped to wait
= 3 x 3²₃
= 11 km

Answer(s): 11 km