City L and City M is 400 km apart. Jenson left City L for City M at 7.00 a.m. travelling at an average speed of 80 km/h. Asher left City L later than Jenson and caught up with him at 9.00 a.m. Asher was travelling at a speed of 96 km/h.

1. At what time did Asher leave City L?
2. How much later did Jenson arrive in City M than Asher? 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 Jenson covered when Asher caught up with Jenson
= 2 x 80
= 160 km

Time that Asher took to travel 160 km
= 160 ÷ 96
= 1²₃ h

1 h = 60 min
²₃ h = ²₃ x 60 = 40 min
1²₃ h = 1 h 40 min

Time that Asher left City L:
1 h 40 min before 9.00 a.m. = 7.20 a.m.

(b)
Remaining distance that they had to cover to reach City M
= 400 - 160
= 240 km

Duration that Asher had to travel before reaching City M
= 240 ÷ 96
= 2¹₂ h

Duration that Jenson had to travel before reaching City M
= 240 ÷ 80
= 3 h

Duration that Jenson took to arrive later than Asher in City M
= 3 - 2¹₂
= ¹₂ h

Answer(s): (a) 7.20 a.m.; (b) ¹₂ h