Liam took 4 hours to travel from Country L to Country M at 70 km/h. Then he travelled from Country M to another country at 1.6 times his original speed. 60% of the distance from Country L to Country M is equal to ¹₄ of the distance from Country M to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country L to Country M
= 4 x 70
= 280 km

Speed from Country M to another country
= 1.6 x 70
= 112 km/h

60% = ⁶⁰₁₀₀ = ³₄

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

5 u = 280
1 u = 280 ÷ 5 = 56

Distance from Country M to the next country
= 12 u
= 12 x 56
= 672 km

Time taken from Country M to the next country
= 672 ÷ 112
= 6 h

Total distance of the whole journey
= 280 + 672
= 952 km

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

Average speed of the whole journey
= 952 ÷ 10
= 95 ²₁₀
= 95 ¹₅ km/h

Answer(s): 95 ¹₅ km/h