City H and City J is 490 km apart. Flynn left City H for City J at 11.00 a.m. travelling at an average speed of 70 km/h. Ben left City H later than Flynn and caught up with him at 1.00 p.m. Ben was travelling at a speed of 80 km/h.

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

(a)
From 11.00 a.m. to 1.00 p.m. = 2 h

Distance that Flynn covered when Ben caught up with Flynn
= 2 x 70
= 140 km

Time that Ben took to travel 140 km
= 140 ÷ 80
= 1³₄ h

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

Time that Ben left City H:
1 h 45 min before 1.00 p.m. = 11.15 a.m.

(b)
Remaining distance that they had to cover to reach City J
= 490 - 140
= 350 km

Duration that Ben had to travel before reaching City J
= 350 ÷ 80
= 4³₈ h

Duration that Flynn had to travel before reaching City J
= 350 ÷ 70
= 5 h

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

Answer(s): (a) 11.15 a.m.; (b) ⁵₈ h