City K and City L is 420 km apart. Vaidev left City K for City L at 11.00 a.m. travelling at an average speed of 70 km/h. Brandon left City K later than Vaidev and caught up with him at 2.00 p.m. Brandon was travelling at a speed of 84 km/h.

1. At what time did Brandon leave City K?
2. How much later did Vaidev arrive in City L than Brandon? 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 Vaidev covered when Brandon caught up with Vaidev
= 3 x 70
= 210 km

Time that Brandon took to travel 210 km
= 210 ÷ 84
= 2¹₂ h

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

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

(b)
Remaining distance that they had to cover to reach City L
= 420 - 210
= 210 km

Duration that Brandon had to travel before reaching City L
= 210 ÷ 84
= 2¹₂ h

Duration that Vaidev had to travel before reaching City L
= 210 ÷ 70
= 3 h

Duration that Vaidev took to arrive later than Brandon in City L
= 3 - 2¹₂
= ¹₂ h

Answer(s): (a) 11.30 a.m.; (b) ¹₂ h