City H and City J is 528 km apart. Ivan left City H for City J at 7.00 a.m. travelling at an average speed of 66 km/h. Bobby left City H later than Ivan and caught up with him at 10.00 a.m. Bobby was travelling at a speed of 88 km/h.

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

(a)
From 7.00 a.m. to 10.00 a.m. = 3 h

Distance that Ivan covered when Bobby caught up with Ivan
= 3 x 66
= 198 km

Time that Bobby took to travel 198 km
= 198 ÷ 88
= 2¹₄ h

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

Time that Bobby left City H:
2 h 15 min before 10.00 a.m. = 7.45 a.m.

(b)
Remaining distance that they had to cover to reach City J
= 528 - 198
= 330 km

Duration that Bobby had to travel before reaching City J
= 330 ÷ 88
= 3³₄ h

Duration that Ivan had to travel before reaching City J
= 330 ÷ 66
= 5 h

Duration that Ivan took to arrive later than Bobby in City J
= 5 - 3³₄
= 1¹₄ h

Answer(s): (a) 7.45 a.m.; (b) 1¹₄ h