City A and City B is 600 km apart. Bryan left City A for City B at 11.00 a.m. travelling at an average speed of 75 km/h. Perry left City A later than Bryan and caught up with him at 2.00 p.m. Perry was travelling at a speed of 90 km/h.

1. At what time did Perry leave City A?
2. How much later did Bryan arrive in City B than Perry? 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 Bryan covered when Perry caught up with Bryan
= 3 x 75
= 225 km

Time that Perry took to travel 225 km
= 225 ÷ 90
= 2¹₂ h

1 h = 60 min
¹₂ h = ¹₂ x 60 = 30 min
2¹₂ h = 2 h 30 min

Time that Perry left City A:
2 h 30 min before 2.00 p.m. = 11.30 a.m.

(b)
Remaining distance that they had to cover to reach City B
= 600 - 225
= 375 km

Duration that Perry had to travel before reaching City B
= 375 ÷ 90
= 4¹₆ h

Duration that Bryan had to travel before reaching City B
= 375 ÷ 75
= 5 h

Duration that Bryan took to arrive later than Perry in City B
= 5 - 4¹₆
= ⁵₆ h

Answer(s): (a) 11.30 a.m.; (b) ⁵₆ h