The distance between Town R and Town S was 181 km. At 09 00, Shannon left Town R and cycled towards Town S. Gem left Town R and cycled towards Town S at 09 45. Gem's cycling speed was 4 km/h faster than Shannon. At 12 00, Gem caught up with Shannon. When Gem was 21 km from Town S, she stopped to wait for Shannon. How far was Shannon from Gem when she stopped to wait for him?
Duration in which Gem cycled for before she caught up with Shannon
= from 09 45 to 12 00
= 2 h 15 min
= 2 ¹⁵₆₀ h
= 2 ¹₄ h

Distance that Gem cycled more than Shannon
= 2¹₄ x 4
= ⁹₄ x 4
= 9 km

Shannon's cycling speed
= 9 x 4
= 36 km/h

Gem's cycling speed
= 36 + 4
= 40 km/h

Distance that Gem cycled before she stopped to wait for Shannon
= 181 - 21
= 160 km

Duration that Gem cycled for after she caught up with Shannon and when she stopped to wait for Shannon
= (160 ÷ 40) - 2¹₄
= 4 - 2¹₄
= 1³₄ h

Distance Shannon was from Gem when she stopped to wait
= 4 x 1³₄
= 7 km

Answer(s): 7 km