City B and City C is 544 km apart. Bobby left City B for City C at 8.00 a.m. travelling at an average speed of 68 km/h. Daniel left City B later than Bobby and caught up with him at 12.00 p.m. Daniel was travelling at a speed of 102 km/h.

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

(a)
From 8.00 a.m. to 12.00 p.m. = 4 h

Distance that Bobby covered when Daniel caught up with Bobby
= 4 x 68
= 272 km

Time that Daniel took to travel 272 km
= 272 ÷ 102
= 2²₃ h

1 h = 60 min
²₃ h = ²₃ x 60 = 40 min
2²₃ h = 2 h 40 min

Time that Daniel left City B:
2 h 40 min before 12.00 p.m. = 9.20 a.m.

(b)
Remaining distance that they had to cover to reach City C
= 544 - 272
= 272 km

Duration that Daniel had to travel before reaching City C
= 272 ÷ 102
= 2²₃ h

Duration that Bobby had to travel before reaching City C
= 272 ÷ 68
= 4 h

Duration that Bobby took to arrive later than Daniel in City C
= 4 - 2²₃
= 1¹₃ h

Answer(s): (a) 9.20 a.m.; (b) 1¹₃ h