City U and City V is 544 km apart. Daniel left City U for City V at 11.00 a.m. travelling at an average speed of 68 km/h. Justin left City U later than Daniel and caught up with him at 2.00 p.m. Justin was travelling at a speed of 72 km/h.

1. At what time did Justin leave City U?
2. How much later did Daniel arrive in City V than Justin? Express your answer in h as a fraction or mixed number.

(a)
From 11.00 a.m. to 2.00 p.m. = 3 h

Distance that Daniel covered when Justin caught up with Daniel
= 3 x 68
= 204 km

Time that Justin took to travel 204 km
= 204 ÷ 72
= 2⁵₆ h

1 h = 60 min
⁵₆ h = ⁵₆ x 60 = 50 min
2⁵₆ h = 2 h 50 min

Time that Justin left City U:
2 h 50 min before 2.00 p.m. = 11.10 a.m.

(b)
Remaining distance that they had to cover to reach City V
= 544 - 204
= 340 km

Duration that Justin had to travel before reaching City V
= 340 ÷ 72
= 4¹³₁₈ h

Duration that Daniel had to travel before reaching City V
= 340 ÷ 68
= 5 h

Duration that Daniel took to arrive later than Justin in City V
= 5 - 4¹³₁₈
= ⁵₁₈ h

Answer(s): (a) 11.10 a.m.; (b) ⁵₁₈ h