Dylan took 6 hours to travel from Country W to Country X at 65 km/h. Then he travelled from Country X to another country at 1.8 times his original speed. 40% of the distance from Country W to Country X is equal to ¹₃ of the distance from Country X to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country W to Country X
= 6 x 65
= 390 km

Speed from Country X to another country
= 1.8 x 65
= 117 km/h

40% = ⁴⁰₁₀₀ = ²₆

²₅ Distance from Country W to Country X = ¹₃ Distance from Country X to next country
²₅ Distance from Country W to Country X = ²₆ Distance from Country X to next country

5 u = 390
1 u = 390 ÷ 5 = 78

Distance from Country X to the next country
= 6 u
= 6 x 78
= 468 km

Time taken from Country X to the next country
= 468 ÷ 117
= 4 h

Total distance of the whole journey
= 390 + 468
= 858 km

Total time taken for the whole journey = 6 + 4 = 10 h

Average speed of the whole journey
= 858 ÷ 10
= 85 ⁸₁₀
= 85 ⁴₅ km/h

Answer(s): 85 ⁴₅ km/h