City A and City B are 504 km apart. At 2.33 p.m., Lee is travelling at a uniform speed left City A for City B while George set off from City B to City A along the same road at a uniform speed, which was 12 km/h slower than that of Lee. The two met at 5.33 p.m.

1. Find the speed of Lee.
2. If George 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 Lee and George to travel from 2.33 p.m. to 5.33 p.m. = 3 h

Average speed of Lee and George
= 504 ÷ 3
= 168 km/h

Lee's speed
= (168 + 12) ÷ 2
= 180 ÷ 2 
= 90 km/h

(b)
George's speed
= 90 - 12
= 78 km/h

Distance that George travelled in 3 h
= 3 x 78
= 234 km

Remaining distance that George needed to travel
= 504 - 234
= 270 km

Time that George needed to reach his destination after the two met
= 270 ÷ 78
= 3³⁶₇₈
= 3⁶₁₃ h

Answer(s): (a) 90 km/h; (b) 3⁶₁₃ h