City M and City N are 396 km apart. At 1.28 p.m., Albert is travelling at a uniform speed left City M for City N while Billy set off from City N to City M along the same road at a uniform speed, which was 6 km/h slower than that of Albert. The two met at 3.28 p.m.

1. Find the speed of Albert.
2. If Billy 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 Albert and Billy to travel from 1.28 p.m. to 3.28 p.m. = 2 h

Average speed of Albert and Billy
= 396 ÷ 2
= 198 km/h

Albert's speed
= (198 + 6) ÷ 2
= 204 ÷ 2 
= 102 km/h

(b)
Billy's speed
= 102 - 6
= 96 km/h

Distance that Billy travelled in 2 h
= 2 x 96
= 192 km

Remaining distance that Billy needed to travel
= 396 - 192
= 204 km

Time that Billy needed to reach his destination after the two met
= 204 ÷ 96
= 2¹²₉₆
= 2¹₈ h

Answer(s): (a) 102 km/h; (b) 2¹₈ h