City Q and City R is 480 km apart. Seth left City Q for City R at 11.00 a.m. travelling at an average speed of 60 km/h. Bryan left City Q later than Seth and caught up with him at 2.00 p.m. Bryan was travelling at a speed of 108 km/h.

1. At what time did Bryan leave City Q?
2. How much later did Seth arrive in City R than Bryan? Express your answer in h as a fraction or mixed number.

(a)
From 11.00 a.m. to 2.00 p.m. = 3 h

Distance that Seth covered when Bryan caught up with Seth
= 3 x 60
= 180 km

Time that Bryan took to travel 180 km
= 180 ÷ 108
= 1²₃ h

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

Time that Bryan left City Q:
1 h 40 min before 2.00 p.m. = 12.20 p.m.

(b)
Remaining distance that they had to cover to reach City R
= 480 - 180
= 300 km

Duration that Bryan had to travel before reaching City R
= 300 ÷ 108
= 2⁷₉ h

Duration that Seth had to travel before reaching City R
= 300 ÷ 60
= 5 h

Duration that Seth took to arrive later than Bryan in City R
= 5 - 2⁷₉
= 2²₉ h

Answer(s): (a) 12.20 p.m.; (b) 2²₉ h