City S and City T is 380 km apart. Glen left City S for City T at 8.00 a.m. travelling at an average speed of 76 km/h. Billy left City S later than Glen and caught up with him at 10.00 a.m. Billy was travelling at a speed of 114 km/h.

1. At what time did Billy leave City S?
2. How much later did Glen arrive in City T than Billy? Express your answer in h as a fraction or mixed number.

(a)
From 8.00 a.m. to 10.00 a.m. = 2 h

Distance that Glen covered when Billy caught up with Glen
= 2 x 76
= 152 km

Time that Billy took to travel 152 km
= 152 ÷ 114
= 1¹₃ h

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

Time that Billy left City S:
1 h 20 min before 10.00 a.m. = 8.40 a.m.

(b)
Remaining distance that they had to cover to reach City T
= 380 - 152
= 228 km

Duration that Billy had to travel before reaching City T
= 228 ÷ 114
= 2 h

Duration that Glen had to travel before reaching City T
= 228 ÷ 76
= 3 h

Duration that Glen took to arrive later than Billy in City T
= 3 - 2
= 1 h

Answer(s): (a) 8.40 a.m.; (b) 1 h