The average number of lemons in Box L, Box M and Box N is 28 and it is 8 more than the average number of starfruits in the 3 boxes. ¹₅ of the starfruits are in Box L and the starfruits in Box L is 80% of the number of starfruits in Box M. If each box has the same number of fruits, what percentage of the fruits in Box N are lemons?
Average number of starfruits
= 28 - 8
= 20

Total number of starfruits
= 3 x 20
= 60

Total number of lemons
= 3 x 28 
= 84

Total number of fruits
= 60 + 84
= 144

Number of fruits in each box
= 144 ÷ 3
= 48

Starfruits in Box L	Starfruits in Box M	Starfruits in Box N	Total starfruits
1x4	4x4		5x4
4x1	5x1
4 u	5 u	11 u	20 u

80% = ⁸⁰₁₀₀ = ⁴₅

The number of starfruits in Box L is repeated.  Make the number of starfruits in Box L the same.  LCM of 1 and 4 is 4. 

Total number of starfruits
= 4 u + 5 u + 11 u
= 20 u

20 u = 60

1 u = 60 ÷ 20 = 3

Number of starfruits in Box N
= 11 u
= 11 x 3
= 33

Number of lemons in Box N
= 48 - 33
= 15

Percentage of the fruits in Box N are lemons
= ¹⁵₄₈ x 100%
= 31.25%

Answer(s): 31.25%