City V and City W is 378 km apart. Harry left City V for City W at 7.00 a.m. travelling at an average speed of 63 km/h. Xavier left City V later than Harry and caught up with him at 11.00 a.m. Xavier was travelling at a speed of 112 km/h.

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

(a)
From 7.00 a.m. to 11.00 a.m. = 4 h

Distance that Harry covered when Xavier caught up with Harry
= 4 x 63
= 252 km

Time that Xavier took to travel 252 km
= 252 ÷ 112
= 2¹₄ h

1 h = 60 min
¹₄ h = ¹₄ x 60 = 15 min
2¹₄ h = 2 h 15 min

Time that Xavier left City V:
2 h 15 min before 11.00 a.m. = 8.45 a.m.

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

Duration that Xavier had to travel before reaching City W
= 126 ÷ 112
= 1¹₈ h

Duration that Harry had to travel before reaching City W
= 126 ÷ 63
= 2 h

Duration that Harry took to arrive later than Xavier in City W
= 2 - 1¹₈
= ⁷₈ h

Answer(s): (a) 8.45 a.m.; (b) ⁷₈ h