The number of yellow files is twice the number of orange files. The number of orange files is 8 more than the number of blue files. The total number of files is 108. The cost of each yellow file is $4.20 and the cost of each blue file is $3.40. The total cost of all the files is $361.40.
- Find the number of blue files.
- Find the cost of a orange file.
(a)
Number of blue files = 1 u
Number of orange files = 1 u + 8
Number of yellow files
= 2(1 u + 8)
= 2 u + 16
Total of number of files
= 1 u + 1 u + 8 + 2 u + 16
= 4 u + 24
4 u + 24 = 108
4 u = 108 - 24
4 u = 84
1 u = 84 ÷ 4 = 21
Number of blue files
= 1 u
= 21
(b)
Number of blue files = 21
Number of orange files
= 21 + 8
= 29
Number of yellow files
= 2 x 29
= 58
Cost of blue files
= 21 x 3.40
= $71.40
Cost of yellow files
= 58 x 4.20
= $243.60
Cost of orange files
= 361.40 - 243.60 - 71.40
= $46.40
Cost of 1 orange file
= 46.40 ÷ 29
= $1.60
Answer(s) (a) 21; (b) $1.60
