Jeremy took 5 hours to travel from Country W to Country X at 65 km/h. Then he travelled from Country X to another country at 1.6 times his original speed. 40% of the distance from Country W to Country X is equal to ¹₄ 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
= 5 x 65
= 325 km

Speed from Country X to another country
= 1.6 x 65
= 104 km/h

40% = ⁴⁰₁₀₀ = ²₅

²₅ Distance from Country W to Country X = ¹₄ Distance from Country X to next country
²₅ Distance from Country W to Country X = ²₈ Distance from Country X to next country

5 u = 325
1 u = 325 ÷ 5 = 65

Distance from Country X to the next country
= 8 u
= 8 x 65
= 520 km

Time taken from Country X to the next country
= 520 ÷ 104
= 5 h

Total distance of the whole journey
= 325 + 520
= 845 km

Total time taken for the whole journey = 5 + 5 = 10 h

Average speed of the whole journey
= 845 ÷ 10
= 84 ⁵₁₀
= 84 ¹₂ km/h

Answer(s): 84 ¹₂ km/h