City V and City W is 378 km apart. Andy left City V for City W at 10.00 a.m. travelling at an average speed of 63 km/h. Archie left City V later than Andy and caught up with him at 12.00 p.m. Archie was travelling at a speed of 84 km/h.

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

(a)
From 10.00 a.m. to 12.00 p.m. = 2 h

Distance that Andy covered when Archie caught up with Andy
= 2 x 63
= 126 km

Time that Archie took to travel 126 km
= 126 ÷ 84
= 1¹₂ h

1 h = 60 min
¹₂ h = ¹₂ x 60 = 30 min
1¹₂ h = 1 h 30 min

Time that Archie left City V:
1 h 30 min before 12.00 p.m. = 10.30 a.m.

(b)
Remaining distance that they had to cover to reach City W
= 378 - 126
= 252 km

Duration that Archie had to travel before reaching City W
= 252 ÷ 84
= 3 h

Duration that Andy had to travel before reaching City W
= 252 ÷ 63
= 4 h

Duration that Andy took to arrive later than Archie in City W
= 4 - 3
= 1 h

Answer(s): (a) 10.30 a.m.; (b) 1 h