Fabian took 5 hours to travel from Country X to Country Y at 68 km/h. Then he travelled from Country Y to another country at 1.5 times his original speed. 70% of the distance from Country X to Country Y is equal to ¹₃ of the distance from Country Y to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country X to Country Y
= 5 x 68
= 340 km

Speed from Country Y to another country
= 1.5 x 68
= 102 km/h

70% = ⁷⁰₁₀₀ = ⁷₅

⁷₁₀ Distance from Country X to Country Y = ¹₃ Distance from Country Y to next country
⁷₁₀ Distance from Country X to Country Y = ⁷₂₁ Distance from Country Y to next country

10 u = 340
1 u = 340 ÷ 10 = 34

Distance from Country Y to the next country
= 21 u
= 21 x 34
= 714 km

Time taken from Country Y to the next country
= 714 ÷ 102
= 7 h

Total distance of the whole journey
= 340 + 714
= 1054 km

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

Average speed of the whole journey
= 1054 ÷ 12
= 87 ¹⁰₁₂
= 87 ⁵₆ km/h

Answer(s): 87 ⁵₆ km/h