City C and City D is 330 km apart. Justin left City C for City D at 9.00 a.m. travelling at an average speed of 66 km/h. Michael left City C later than Justin and caught up with him at 11.00 a.m. Michael was travelling at a speed of 99 km/h.

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

(a)
From 9.00 a.m. to 11.00 a.m. = 2 h

Distance that Justin covered when Michael caught up with Justin
= 2 x 66
= 132 km

Time that Michael took to travel 132 km
= 132 ÷ 99
= 1¹₃ h

1 h = 60 min
¹₃ h = ¹₃ x 60 = 20 min
1¹₃ h = 1 h 20 min

Time that Michael left City C:
1 h 20 min before 11.00 a.m. = 9.40 a.m.

(b)
Remaining distance that they had to cover to reach City D
= 330 - 132
= 198 km

Duration that Michael had to travel before reaching City D
= 198 ÷ 99
= 2 h

Duration that Justin had to travel before reaching City D
= 198 ÷ 66
= 3 h

Duration that Justin took to arrive later than Michael in City D
= 3 - 2
= 1 h

Answer(s): (a) 9.40 a.m.; (b) 1 h