Nick took 3 hours to travel from Country N to Country P at 50 km/h. Then he travelled from Country P to another country at 1.4 times his original speed. 70% of the distance from Country N to Country P is equal to ¹₄ of the distance from Country P to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country N to Country P
= 3 x 50
= 150 km

Speed from Country P to another country
= 1.4 x 50
= 70 km/h

70% = ⁷⁰₁₀₀ = ⁷₃

⁷₁₀ Distance from Country N to Country P = ¹₄ Distance from Country P to next country
⁷₁₀ Distance from Country N to Country P = ⁷₂₈ Distance from Country P to next country

10 u = 150
1 u = 150 ÷ 10 = 15

Distance from Country P to the next country
= 28 u
= 28 x 15
= 420 km

Time taken from Country P to the next country
= 420 ÷ 70
= 6 h

Total distance of the whole journey
= 150 + 420
= 570 km

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

Average speed of the whole journey
= 570 ÷ 9
= 63 ³₉
= 63 ¹₃ km/h

Answer(s): 63 ¹₃ km/h