Will took 4 hours to travel from Country B to Country C at 55 km/h. Then he travelled from Country C to another country at 1.2 times his original speed. 60% of the distance from Country B to Country C is equal to ¹₃ of the distance from Country C to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country B to Country C
= 4 x 55
= 220 km

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

60% = ⁶⁰₁₀₀ = ³₄

³₅ Distance from Country B to Country C = ¹₃ Distance from Country C to next country
³₅ Distance from Country B to Country C = ³₉ Distance from Country C to next country

5 u = 220
1 u = 220 ÷ 5 = 44

Distance from Country C to the next country
= 9 u
= 9 x 44
= 396 km

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

Total distance of the whole journey
= 220 + 396
= 616 km

Total time taken for the whole journey = 4 + 6 = 10 h

Average speed of the whole journey
= 616 ÷ 10
= 61 ⁶₁₀
= 61 ³₅ km/h

Answer(s): 61 ³₅ km/h