City H and City J is 441 km apart. Vaidev left City H for City J at 7.00 a.m. travelling at an average speed of 63 km/h. Flynn left City H later than Vaidev and caught up with him at 9.00 a.m. Flynn was travelling at a speed of 72 km/h.

1. At what time did Flynn leave City H?
2. How much later did Vaidev arrive in City J than Flynn? Express your answer in h as a fraction or mixed number.

(a)
From 7.00 a.m. to 9.00 a.m. = 2 h

Distance that Vaidev covered when Flynn caught up with Vaidev
= 2 x 63
= 126 km

Time that Flynn took to travel 126 km
= 126 ÷ 72
= 1³₄ h

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

Time that Flynn left City H:
1 h 45 min before 9.00 a.m. = 7.15 a.m.

(b)
Remaining distance that they had to cover to reach City J
= 441 - 126
= 315 km

Duration that Flynn had to travel before reaching City J
= 315 ÷ 72
= 4³₈ h

Duration that Vaidev had to travel before reaching City J
= 315 ÷ 63
= 5 h

Duration that Vaidev took to arrive later than Flynn in City J
= 5 - 4³₈
= ⁵₈ h

Answer(s): (a) 7.15 a.m.; (b) ⁵₈ h