City Q and City R is 288 km apart. Warren left City Q for City R at 10.00 a.m. travelling at an average speed of 72 km/h. Howard left City Q later than Warren and caught up with him at 12.00 p.m. Howard was travelling at a speed of 108 km/h.

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

(a)
From 10.00 a.m. to 12.00 p.m. = 2 h

Distance that Warren covered when Howard caught up with Warren
= 2 x 72
= 144 km

Time that Howard took to travel 144 km
= 144 ÷ 108
= 1¹₃ h

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

Time that Howard left City Q:
1 h 20 min before 12.00 p.m. = 10.40 a.m.

(b)
Remaining distance that they had to cover to reach City R
= 288 - 144
= 144 km

Duration that Howard had to travel before reaching City R
= 144 ÷ 108
= 1¹₃ h

Duration that Warren had to travel before reaching City R
= 144 ÷ 72
= 2 h

Duration that Warren took to arrive later than Howard in City R
= 2 - 1¹₃
= ²₃ h

Answer(s): (a) 10.40 a.m.; (b) ²₃ h