The average number of starfruits in Box P, Box Q and Box R is 16 and it is 8 more than the average number of passion fruits in the 3 boxes. ¹₃ of the passion fruits are in Box P and the passion fruits in Box P is 80% of the number of passion fruits in Box Q. If each box has the same number of fruits, what percentage of the fruits in Box R are starfruits?
Average number of passion fruits
= 16 - 8
= 8

Total number of passion fruits
= 3 x 8
= 24

Total number of starfruits
= 3 x 16 
= 48

Total number of fruits
= 24 + 48
= 72

Number of fruits in each box
= 72 ÷ 3
= 24

Passion fruits in Box P	Passion fruits in Box Q	Passion fruits in Box R	Total passion fruits
1x4	2x4		3x4
4x1	5x1
4 u	5 u	3 u	12 u

80% = ⁸⁰₁₀₀ = ⁴₅

The number of passion fruits in Box P is repeated.  Make the number of passion fruits in Box P the same.  LCM of 1 and 4 is 4. 

Total number of passion fruits
= 4 u + 5 u + 3 u
= 12 u

12 u = 24

1 u = 24 ÷ 12 = 2

Number of passion fruits in Box R
= 3 u
= 3 x 2
= 6

Number of starfruits in Box R
= 24 - 6
= 18

Percentage of the fruits in Box R are starfruits
= ¹⁸₂₄ x 100%
= 75%

Answer(s): 75%