City G and City H is 612 km apart. Mark left City G for City H at 9.00 a.m. travelling at an average speed of 68 km/h. Jenson left City G later than Mark and caught up with him at 1.00 p.m. Jenson was travelling at a speed of 96 km/h.

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

(a)
From 9.00 a.m. to 1.00 p.m. = 4 h

Distance that Mark covered when Jenson caught up with Mark
= 4 x 68
= 272 km

Time that Jenson took to travel 272 km
= 272 ÷ 96
= 2⁵₆ h

1 h = 60 min
⁵₆ h = ⁵₆ x 60 = 50 min
2⁵₆ h = 2 h 50 min

Time that Jenson left City G:
2 h 50 min before 1.00 p.m. = 10.10 a.m.

(b)
Remaining distance that they had to cover to reach City H
= 612 - 272
= 340 km

Duration that Jenson had to travel before reaching City H
= 340 ÷ 96
= 3¹³₂₄ h

Duration that Mark had to travel before reaching City H
= 340 ÷ 68
= 5 h

Duration that Mark took to arrive later than Jenson in City H
= 5 - 3¹³₂₄
= 1¹¹₂₄ h

Answer(s): (a) 10.10 a.m.; (b) 1¹¹₂₄ h