City Z and City A is 441 km apart. Warren left City Z for City A at 8.00 a.m. travelling at an average speed of 63 km/h. George left City Z later than Warren and caught up with him at 11.00 a.m. George was travelling at a speed of 108 km/h.

1. At what time did George leave City Z?
2. How much later did Warren arrive in City A than George? Express your answer in h as a fraction or mixed number.

(a)
From 8.00 a.m. to 11.00 a.m. = 3 h

Distance that Warren covered when George caught up with Warren
= 3 x 63
= 189 km

Time that George took to travel 189 km
= 189 ÷ 108
= 1³₄ h

1 h = 60 min
³₄ h = ³₄ x 60 = 45 min
1³₄ h = 1 h 45 min

Time that George left City Z:
1 h 45 min before 11.00 a.m. = 9.15 a.m.

(b)
Remaining distance that they had to cover to reach City A
= 441 - 189
= 252 km

Duration that George had to travel before reaching City A
= 252 ÷ 108
= 2¹₃ h

Duration that Warren had to travel before reaching City A
= 252 ÷ 63
= 4 h

Duration that Warren took to arrive later than George in City A
= 4 - 2¹₃
= 1²₃ h

Answer(s): (a) 9.15 a.m.; (b) 1²₃ h