The number of green files is twice the number of orange files. The number of orange files is 5 more than the number of brown files. The total number of files is 103. The cost of each green file is $4.40 and the cost of each brown file is $3.20. The total cost of all the files is $343.10.

1. Find the number of brown files.
2. Find the cost of a orange file.

(a)
Number of brown files = 1 u
Number of orange files = 1 u + 5

Number of green files
= 2(1 u + 5)
= 2 u + 10

Total of number of files
= 1 u + 1 u + 5 + 2 u + 10
= 4 u + 15

4 u + 15 = 103
4 u = 103 - 15
4 u = 88

1 u = 88 ÷ 4 = 22

Number of brown files
= 1 u
= 22

(b)
Number of brown files = 22

Number of orange files
=  22 + 5
= 27

Number of green files
= 2 x 27
= 54

Cost of brown files 
= 22 x 3.20
= $70.40

Cost of green files 
= 54 x 4.40
= $237.60

Cost of orange files
= 343.10 - 237.60 - 70.40
= $35.10

Cost of 1 orange file
= 35.10 ÷ 27
= $1.30

Answer(s) (a) 22; (b) $1.30