Warren started driving from Town Q towards Town R at 13 30 at an average speed of 60 km/h. David began driving from Town Q towards Town R at 15 10 at an average speed of 100 km/h.

1. At what time did David pass Warren on the road?
2. 1¹₄ hours after passing Warren, David reached Town R. At what time did Warren reach Town R?

(a)
From 13 30 to 15 10 = 1 h 40 min

Time that Warren travelled before David started driving = 1 h 40 min

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

Distance that Warren travelled before David started driving
= 1²₃ x 60
= ⁵₃ x 60
= 100 km

Difference between David's and Warren's speed
= 100 - 60
= 40 km/h

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

2 h 30 min after 15 10 = 17 40

Time that David passed Warren on the road = 17 40

(b)
1¹₄ h = 1 h 15 min

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

3 h 45 min = 3⁴⁵₆₀h = 3³₄h

Distance between Town Q and Town R
= 3³₄ x 100
= 375 km

Time that Warren travelled from Town Q to Town R
= 375 ÷ 60
= 6.25 h
= 6 h 15 min

6 h 15 min after 13 30 = 19 45

Time that Warren reached Town R = 19 45

Answer: (a) 17 40; (b) 19 45