Fabian took 4 hours to travel from Country M to Country N at 60 km/h. Then he travelled from Country N to another country at 1.6 times his original speed. 60% of the distance from Country M to Country N is equal to ¹₄ of the distance from Country N to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country M to Country N
= 4 x 60
= 240 km

Speed from Country N to another country
= 1.6 x 60
= 96 km/h

60% = ⁶⁰₁₀₀ = ³₄

³₅ Distance from Country M to Country N = ¹₄ Distance from Country N to next country
³₅ Distance from Country M to Country N = ³₁₂ Distance from Country N to next country

5 u = 240
1 u = 240 ÷ 5 = 48

Distance from Country N to the next country
= 12 u
= 12 x 48
= 576 km

Time taken from Country N to the next country
= 576 ÷ 96
= 6 h

Total distance of the whole journey
= 240 + 576
= 816 km

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

Average speed of the whole journey
= 816 ÷ 10
= 81 ⁶₁₀
= 81 ³₅ km/h

Answer(s): 81 ³₅ km/h