Ahmad took 6 hours to travel from Country M to Country N at 56 km/h. Then he travelled from Country N to another country at 1.5 times his original speed. 25% of the distance from Country M to Country N is equal to ¹₃ of the distance from Country N to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country M to Country N
= 6 x 56
= 336 km

Speed from Country N to another country
= 1.5 x 56
= 84 km/h

25% = ²⁵₁₀₀ = ¹₆

¹₄ Distance from Country M to Country N = ¹₃ Distance from Country N to next country
¹₄ Distance from Country M to Country N = ¹₃ Distance from Country N to next country

4 u = 336
1 u = 336 ÷ 4 = 84

Distance from Country N to the next country
= 3 u
= 3 x 84
= 252 km

Time taken from Country N to the next country
= 252 ÷ 84
= 3 h

Total distance of the whole journey
= 336 + 252
= 588 km

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

Average speed of the whole journey
= 588 ÷ 9
= 65 ³₉
= 65 ¹₃ km/h

Answer(s): 65 ¹₃ km/h