Albert took 4 hours to travel from Country S to Country T at 50 km/h. Then he travelled from Country T to another country at 1.3 times his original speed. 65% 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
= 4 x 50
= 200 km

Speed from Country T to another country
= 1.3 x 50
= 65 km/h

65% = ⁶⁵₁₀₀ = ¹³₄

¹³₂₀ Distance from Country S to Country T = ¹₆ Distance from Country T to next country
¹³₂₀ Distance from Country S to Country T = ¹³₇₈ Distance from Country T to next country

20 u = 200
1 u = 200 ÷ 20 = 10

Distance from Country T to the next country
= 78 u
= 78 x 10
= 780 km

Time taken from Country T to the next country
= 780 ÷ 65
= 12 h

Total distance of the whole journey
= 200 + 780
= 980 km

Total time taken for the whole journey = 4 + 12 = 16 h

Average speed of the whole journey
= 980 ÷ 16
= 61 ⁴₁₆
= 61 ¹₄ km/h

Answer(s): 61 ¹₄ km/h