City R and City S are 384 km apart. At 4.17 p.m., Dylan is travelling at a uniform speed left City R for City S while Oscar set off from City S to City R along the same road at a uniform speed, which was 8 km/h slower than that of Dylan. The two met at 7.17 p.m.

1. Find the speed of Dylan.
2. If Oscar continued to travel at the same speed, how long would it take for him to reach his destination after the two met? Express your answer in mixed number.

(a)
Time taken for Dylan and Oscar to travel from 4.17 p.m. to 7.17 p.m. = 3 h

Average speed of Dylan and Oscar
= 384 ÷ 3
= 128 km/h

Dylan's speed
= (128 + 8) ÷ 2
= 136 ÷ 2 
= 68 km/h

(b)
Oscar's speed
= 68 - 8
= 60 km/h

Distance that Oscar travelled in 3 h
= 3 x 60
= 180 km

Remaining distance that Oscar needed to travel
= 384 - 180
= 204 km

Time that Oscar needed to reach his destination after the two met
= 204 ÷ 60
= 3²⁴₆₀
= 3²₅ h

Answer(s): (a) 68 km/h; (b) 3²₅ h