Simon took 6 hours to travel from Country J to Country K at 80 km/h. Then he travelled from Country K to another country at 1.3 times his original speed. 65% of the distance from Country J to Country K is equal to ¹₃ of the distance from Country K to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country J to Country K
= 6 x 80
= 480 km

Speed from Country K to another country
= 1.3 x 80
= 104 km/h

65% = ⁶⁵₁₀₀ = ¹³₆

¹³₂₀ Distance from Country J to Country K = ¹₃ Distance from Country K to next country
¹³₂₀ Distance from Country J to Country K = ¹³₃₉ Distance from Country K to next country

20 u = 480
1 u = 480 ÷ 20 = 24

Distance from Country K to the next country
= 39 u
= 39 x 24
= 936 km

Time taken from Country K to the next country
= 936 ÷ 104
= 9 h

Total distance of the whole journey
= 480 + 936
= 1416 km

Total time taken for the whole journey = 6 + 9 = 15 h

Average speed of the whole journey
= 1416 ÷ 15
= 94 ⁶₁₅
= 94 ²₅ km/h

Answer(s): 94 ²₅ km/h