City D and City E is 567 km apart. Ivan left City D for City E at 7.00 a.m. travelling at an average speed of 63 km/h. Lee left City D later than Ivan and caught up with him at 11.00 a.m. Lee was travelling at a speed of 112 km/h.

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

(a)
From 7.00 a.m. to 11.00 a.m. = 4 h

Distance that Ivan covered when Lee caught up with Ivan
= 4 x 63
= 252 km

Time that Lee took to travel 252 km
= 252 ÷ 112
= 2¹₄ h

1 h = 60 min
¹₄ h = ¹₄ x 60 = 15 min
2¹₄ h = 2 h 15 min

Time that Lee left City D:
2 h 15 min before 11.00 a.m. = 8.45 a.m.

(b)
Remaining distance that they had to cover to reach City E
= 567 - 252
= 315 km

Duration that Lee had to travel before reaching City E
= 315 ÷ 112
= 2¹³₁₆ h

Duration that Ivan had to travel before reaching City E
= 315 ÷ 63
= 5 h

Duration that Ivan took to arrive later than Lee in City E
= 5 - 2¹³₁₆
= 2³₁₆ h

Answer(s): (a) 8.45 a.m.; (b) 2³₁₆ h