Sean started driving from Town D towards Town E at 14 40 at an average speed of 60 km/h. Harry began driving from Town D towards Town E at 16 20 at an average speed of 100 km/h.

1. At what time did Harry pass Sean on the road?
2. 1¹₄ hours after passing Sean, Harry reached Town E. At what time did Sean reach Town E?

(a)
From 14 40 to 16 20 = 1 h 40 min

Time that Sean travelled before Harry started driving = 1 h 40 min

1 h = 60 min
1 h 40 min = 1⁴⁰₆₀ h = 1²₃ h

Distance that Sean travelled before Harry started driving
= 1²₃ x 60
= ⁵₃ x 60
= 100 km

Difference between Harry's and Sean's speed
= 100 - 60
= 40 km/h

Time that Harry took to catch up with Sean
= 100 ÷ 40
= 2.5 h
= 2 h 30 min

2 h 30 min after 16 20 = 18 50

Time that Harry passed Sean on the road = 18 50

(b)
1¹₄ h = 1 h 15 min

Total time that Harry travelled
= 1 h 15 min + 2 h 30 min
= 3 h 45 min

3 h 45 min = 3⁴⁵₆₀h = 3³₄h

Distance between Town D and Town E
= 3³₄ x 100
= 375 km

Time that Sean travelled from Town D to Town E
= 375 ÷ 60
= 6.25 h
= 6 h 15 min

6 h 15 min after 14 40 = 20 55

Time that Sean reached Town E = 20 55

Answer: (a) 18 50; (b) 20 55