City K and City L is 612 km apart. John left City K for City L at 11.00 a.m. travelling at an average speed of 68 km/h. Eric left City K later than John and caught up with him at 3.00 p.m. Eric was travelling at a speed of 96 km/h.

1. At what time did Eric leave City K?
2. How much later did John arrive in City L than Eric? Express your answer in h as a fraction or mixed number.

(a)
From 11.00 a.m. to 3.00 p.m. = 4 h

Distance that John covered when Eric caught up with John
= 4 x 68
= 272 km

Time that Eric took to travel 272 km
= 272 ÷ 96
= 2⁵₆ h

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

Time that Eric left City K:
2 h 50 min before 3.00 p.m. = 12.10 p.m.

(b)
Remaining distance that they had to cover to reach City L
= 612 - 272
= 340 km

Duration that Eric had to travel before reaching City L
= 340 ÷ 96
= 3¹³₂₄ h

Duration that John had to travel before reaching City L
= 340 ÷ 68
= 5 h

Duration that John took to arrive later than Eric in City L
= 5 - 3¹³₂₄
= 1¹¹₂₄ h

Answer(s): (a) 12.10 p.m.; (b) 1¹¹₂₄ h