Albert took 5 hours to travel from Country U to Country V at 68 km/h. Then he travelled from Country V to another country at 1.5 times his original speed. 45% of the distance from Country U to Country V is equal to ¹₆ of the distance from Country V to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country U to Country V
= 5 x 68
= 340 km

Speed from Country V to another country
= 1.5 x 68
= 102 km/h

45% = ⁴⁵₁₀₀ = ⁹₅

⁹₂₀ Distance from Country U to Country V = ¹₆ Distance from Country V to next country
⁹₂₀ Distance from Country U to Country V = ⁹₅₄ Distance from Country V to next country

20 u = 340
1 u = 340 ÷ 20 = 17

Distance from Country V to the next country
= 54 u
= 54 x 17
= 918 km

Time taken from Country V to the next country
= 918 ÷ 102
= 9 h

Total distance of the whole journey
= 340 + 918
= 1258 km

Total time taken for the whole journey = 5 + 9 = 14 h

Average speed of the whole journey
= 1258 ÷ 14
= 89 ¹²₁₄
= 89 ⁶₇ km/h

Answer(s): 89 ⁶₇ km/h