City L and City M are 432 km apart. At 4.39 p.m., Ethan is travelling at a uniform speed left City L for City M while Jenson set off from City M to City L along the same road at a uniform speed, which was 12 km/h slower than that of Ethan. The two met at 6.39 p.m.

1. Find the speed of Ethan.
2. If Jenson 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 Ethan and Jenson to travel from 4.39 p.m. to 6.39 p.m. = 2 h

Average speed of Ethan and Jenson
= 432 ÷ 2
= 216 km/h

Ethan's speed
= (216 + 12) ÷ 2
= 228 ÷ 2 
= 114 km/h

(b)
Jenson's speed
= 114 - 12
= 102 km/h

Distance that Jenson travelled in 2 h
= 2 x 102
= 204 km

Remaining distance that Jenson needed to travel
= 432 - 204
= 228 km

Time that Jenson needed to reach his destination after the two met
= 228 ÷ 102
= 2²⁴₁₀₂
= 2⁴₁₇ h

Answer(s): (a) 114 km/h; (b) 2⁴₁₇ h