City E and City F is 544 km apart. Tom left City E for City F at 10.00 a.m. travelling at an average speed of 68 km/h. Vincent left City E later than Tom and caught up with him at 1.00 p.m. Vincent was travelling at a speed of 72 km/h.

1. At what time did Vincent leave City E?
2. How much later did Tom arrive in City F than Vincent? Express your answer in h as a fraction or mixed number.

(a)
From 10.00 a.m. to 1.00 p.m. = 3 h

Distance that Tom covered when Vincent caught up with Tom
= 3 x 68
= 204 km

Time that Vincent took to travel 204 km
= 204 ÷ 72
= 2⁵₆ h

1 h = 60 min
⁵₆ h = ⁵₆ x 60 = 50 min
2⁵₆ h = 2 h 50 min

Time that Vincent left City E:
2 h 50 min before 1.00 p.m. = 10.10 a.m.

(b)
Remaining distance that they had to cover to reach City F
= 544 - 204
= 340 km

Duration that Vincent had to travel before reaching City F
= 340 ÷ 72
= 4¹³₁₈ h

Duration that Tom had to travel before reaching City F
= 340 ÷ 68
= 5 h

Duration that Tom took to arrive later than Vincent in City F
= 5 - 4¹³₁₈
= ⁵₁₈ h

Answer(s): (a) 10.10 a.m.; (b) ⁵₁₈ h