City N and City P is 280 km apart. Paul left City N for City P at 7.00 a.m. travelling at an average speed of 70 km/h. Perry left City N later than Paul and caught up with him at 9.00 a.m. Perry was travelling at a speed of 105 km/h.

1. At what time did Perry leave City N?
2. How much later did Paul arrive in City P than Perry? 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 Paul covered when Perry caught up with Paul
= 2 x 70
= 140 km

Time that Perry took to travel 140 km
= 140 ÷ 105
= 1¹₃ h

1 h = 60 min
¹₃ h = ¹₃ x 60 = 20 min
1¹₃ h = 1 h 20 min

Time that Perry left City N:
1 h 20 min before 9.00 a.m. = 7.40 a.m.

(b)
Remaining distance that they had to cover to reach City P
= 280 - 140
= 140 km

Duration that Perry had to travel before reaching City P
= 140 ÷ 105
= 1¹₃ h

Duration that Paul had to travel before reaching City P
= 140 ÷ 70
= 2 h

Duration that Paul took to arrive later than Perry in City P
= 2 - 1¹₃
= ²₃ h

Answer(s): (a) 7.40 a.m.; (b) ²₃ h