City A and City B is 420 km apart. Ryan left City A for City B at 9.00 a.m. travelling at an average speed of 60 km/h. Reggie left City A later than Ryan and caught up with him at 11.00 a.m. Reggie was travelling at a speed of 80 km/h.

1. At what time did Reggie leave City A?
2. How much later did Ryan arrive in City B than Reggie? Express your answer in h as a fraction or mixed number.

(a)
From 9.00 a.m. to 11.00 a.m. = 2 h

Distance that Ryan covered when Reggie caught up with Ryan
= 2 x 60
= 120 km

Time that Reggie took to travel 120 km
= 120 ÷ 80
= 1¹₂ h

1 h = 60 min
¹₂ h = ¹₂ x 60 = 30 min
1¹₂ h = 1 h 30 min

Time that Reggie left City A:
1 h 30 min before 11.00 a.m. = 9.30 a.m.

(b)
Remaining distance that they had to cover to reach City B
= 420 - 120
= 300 km

Duration that Reggie had to travel before reaching City B
= 300 ÷ 80
= 3³₄ h

Duration that Ryan had to travel before reaching City B
= 300 ÷ 60
= 5 h

Duration that Ryan took to arrive later than Reggie in City B
= 5 - 3³₄
= 1¹₄ h

Answer(s): (a) 9.30 a.m.; (b) 1¹₄ h