City J and City K are 460 km apart. At 6.47 p.m., Ben is travelling at a uniform speed left City J for City K while Will set off from City K to City J along the same road at a uniform speed, which was 11 km/h slower than that of Ben. The two met at 10.47 p.m.

1. Find the speed of Ben.
2. If Will 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 Ben and Will to travel from 6.47 p.m. to 10.47 p.m. = 4 h

Average speed of Ben and Will
= 460 ÷ 4
= 115 km/h

Ben's speed
= (115 + 11) ÷ 2
= 126 ÷ 2 
= 63 km/h

(b)
Will's speed
= 63 - 11
= 52 km/h

Distance that Will travelled in 4 h
= 4 x 52
= 208 km

Remaining distance that Will needed to travel
= 460 - 208
= 252 km

Time that Will needed to reach his destination after the two met
= 252 ÷ 52
= 4⁴⁴₅₂
= 4¹¹₁₃ h

Answer(s): (a) 63 km/h; (b) 4¹¹₁₃ h