Sean took 3 hours to travel from Country T to Country U at 55 km/h. Then he travelled from Country U to another country at 1.2 times his original speed. 60% of the distance from Country T to Country U is equal to ¹₄ of the distance from Country U to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country T to Country U
= 3 x 55
= 165 km

Speed from Country U to another country
= 1.2 x 55
= 66 km/h

60% = ⁶⁰₁₀₀ = ³₃

³₅ Distance from Country T to Country U = ¹₄ Distance from Country U to next country
³₅ Distance from Country T to Country U = ³₁₂ Distance from Country U to next country

5 u = 165
1 u = 165 ÷ 5 = 33

Distance from Country U to the next country
= 12 u
= 12 x 33
= 396 km

Time taken from Country U to the next country
= 396 ÷ 66
= 6 h

Total distance of the whole journey
= 165 + 396
= 561 km

Total time taken for the whole journey = 3 + 6 = 9 h

Average speed of the whole journey
= 561 ÷ 9
= 62 ³₉
= 62 ¹₃ km/h

Answer(s): 62 ¹₃ km/h