Daniel took 6 hours to travel from Country K to Country L at 65 km/h. Then he travelled from Country L to another country at 1.8 times his original speed. 30% of the distance from Country K to Country L is equal to ¹₄ of the distance from Country L to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country K to Country L
= 6 x 65
= 390 km

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

30% = ³⁰₁₀₀ = ³₆

³₁₀ Distance from Country K to Country L = ¹₄ Distance from Country L to next country
³₁₀ Distance from Country K to Country L = ³₁₂ Distance from Country L to next country

10 u = 390
1 u = 390 ÷ 10 = 39

Distance from Country L to the next country
= 12 u
= 12 x 39
= 468 km

Time taken from Country L 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