Tim took 6 hours to travel from Country S to Country T at 62 km/h. Then he travelled from Country T to another country at 1.5 times his original speed. 25% of the distance from Country S to Country T is equal to ¹₆ of the distance from Country T to the next country. Find the average speed for the whole journey and express it as a mixed number.
Distance he travelled from Country S to Country T
= 6 x 62
= 372 km

Speed from Country T to another country
= 1.5 x 62
= 93 km/h

25% = ²⁵₁₀₀ = ¹₆

¹₄ Distance from Country S to Country T = ¹₆ Distance from Country T to next country
¹₄ Distance from Country S to Country T = ¹₆ Distance from Country T to next country

4 u = 372
1 u = 372 ÷ 4 = 93

Distance from Country T to the next country
= 6 u
= 6 x 93
= 558 km

Time taken from Country T to the next country
= 558 ÷ 93
= 6 h

Total distance of the whole journey
= 372 + 558
= 930 km

Total time taken for the whole journey = 6 + 6 = 12 h

Average speed of the whole journey
= 930 ÷ 12
= 77 ⁶₁₂
= 77 ¹₂ km/h

Answer(s): 77 ¹₂ km/h