Julian took 5 hours to travel from Country U to Country V at 66 km/h. Then he travelled from Country V to another country at 1.5 times his original speed. 70% of the distance from Country U to Country V is equal to ¹₃ of the distance from Country V to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country U to Country V
= 5 x 66
= 330 km

Speed from Country V to another country
= 1.5 x 66
= 99 km/h

70% = ⁷⁰₁₀₀ = ⁷₅

⁷₁₀ Distance from Country U to Country V = ¹₃ Distance from Country V to next country
⁷₁₀ Distance from Country U to Country V = ⁷₂₁ Distance from Country V to next country

10 u = 330
1 u = 330 ÷ 10 = 33

Distance from Country V to the next country
= 21 u
= 21 x 33
= 693 km

Time taken from Country V to the next country
= 693 ÷ 99
= 7 h

Total distance of the whole journey
= 330 + 693
= 1023 km

Total time taken for the whole journey = 5 + 7 = 12 h

Average speed of the whole journey
= 1023 ÷ 12
= 85 ³₁₂
= 85 ¹₄ km/h

Answer(s): 85 ¹₄ km/h