Justin started driving from City R towards City S at 14 30 at an average speed of 60 km/h. Warren began driving from City R towards City S at 16 20 at an average speed of 110 km/h.

1. At what time did Warren pass Justin on the road?
2. 1¹₁₀ hours after passing Justin, Warren reached City S. At what time did Justin reach City S?

(a)
From 14 30 to 16 20 = 1 h 50 min

Time that Justin travelled before Warren started driving = 1 h 50 min

1 h = 60 min
1 h 50 min = 1⁵⁰₆₀ h = 1⁵₆ h

Distance that Justin travelled before Warren started driving
= 1⁵₆ x 60
= ¹¹₆ x 60
= 110 km

Difference between Warren's and Justin's speed
= 110 - 60
= 50 km/h

Time that Warren took to catch up with Justin
= 110 ÷ 50
= 2.2 h
= 2 h 12 min

2 h 12 min after 16 20 = 18 32

Time that Warren passed Justin on the road = 18 32

(b)
1¹₁₀ h = 1 h 6 min

Total time that Warren travelled
= 1 h 6 min + 2 h 12 min
= 3 h 18 min

3 h 18 min = 3¹⁸₆₀h = 3³₁₀h

Distance between City R and City S
= 3³₁₀ x 110
= 363 km

Time that Justin travelled from City R to City S
= 363 ÷ 60
= 6.05 h
= 6 h 3 min

6 h 3 min after 14 30 = 20 33

Time that Justin reached City S = 20 33

Answer: (a) 18 32; (b) 20 33