Brandon took 5 hours to travel from Country L to Country M at 60 km/h. Then he travelled from Country M to another country at 1.5 times his original speed. 70% of the distance from Country L to Country M is equal to ¹₃ 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
= 5 x 60
= 300 km

Speed from Country M to another country
= 1.5 x 60
= 90 km/h

70% = ⁷⁰₁₀₀ = ⁷₅

⁷₁₀ Distance from Country L to Country M = ¹₃ Distance from Country M to next country
⁷₁₀ Distance from Country L to Country M = ⁷₂₁ Distance from Country M to next country

10 u = 300
1 u = 300 ÷ 10 = 30

Distance from Country M to the next country
= 21 u
= 21 x 30
= 630 km

Time taken from Country M to the next country
= 630 ÷ 90
= 7 h

Total distance of the whole journey
= 300 + 630
= 930 km

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

Average speed of the whole journey
= 930 ÷ 12
= 77 ⁶₁₂
= 77 ¹₂ km/h

Answer(s): 77 ¹₂ km/h