Bobby took 3 hours to travel from Country F to Country G at 60 km/h. Then he travelled from Country G to another country at 1.8 times his original speed. 70% of the distance from Country F to Country G is equal to ¹₆ of the distance from Country G to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country F to Country G
= 3 x 60
= 180 km

Speed from Country G to another country
= 1.8 x 60
= 108 km/h

70% = ⁷⁰₁₀₀ = ⁷₃

⁷₁₀ Distance from Country F to Country G = ¹₆ Distance from Country G to next country
⁷₁₀ Distance from Country F to Country G = ⁷₄₂ Distance from Country G to next country

10 u = 180
1 u = 180 ÷ 10 = 18

Distance from Country G to the next country
= 42 u
= 42 x 18
= 756 km

Time taken from Country G to the next country
= 756 ÷ 108
= 7 h

Total distance of the whole journey
= 180 + 756
= 936 km

Total time taken for the whole journey = 3 + 7 = 10 h

Average speed of the whole journey
= 936 ÷ 10
= 93 ⁶₁₀
= 93 ³₅ km/h

Answer(s): 93 ³₅ km/h