Neave took 6 hours to travel from Country U to Country V at 55 km/h. Then he travelled from Country V to another country at 1.8 times his original speed. 60% 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
= 6 x 55
= 330 km

Speed from Country V to another country
= 1.8 x 55
= 99 km/h

60% = ⁶⁰₁₀₀ = ³₆

³₅ Distance from Country U to Country V = ¹₆ Distance from Country V to next country
³₅ Distance from Country U to Country V = ³₁₈ Distance from Country V to next country

5 u = 330
1 u = 330 ÷ 5 = 66

Distance from Country V to the next country
= 18 u
= 18 x 66
= 1188 km

Time taken from Country V to the next country
= 1188 ÷ 99
= 12 h

Total distance of the whole journey
= 330 + 1188
= 1518 km

Total time taken for the whole journey = 6 + 12 = 18 h

Average speed of the whole journey
= 1518 ÷ 18
= 84 ⁶₁₈
= 84 ¹₃ km/h

Answer(s): 84 ¹₃ km/h