The number of red folders is twice the number of brown folders. The number of brown folders is 6 more than the number of blue folders. The total number of folders is 106. The cost of each red folder is $3.90 and the cost of each blue folder is $1.90. The total cost of all the folders is $313.40.
- Find the number of blue folders.
- Find the cost of a brown folder.
(a)
Number of blue folders = 1 u
Number of brown folders = 1 u + 6
Number of red folders
= 2(1 u + 6)
= 2 u + 12
Total of number of folders
= 1 u + 1 u + 6 + 2 u + 12
= 4 u + 18
4 u + 18 = 106
4 u = 106 - 18
4 u = 88
1 u = 88 ÷ 4 = 22
Number of blue folders
= 1 u
= 22
(b)
Number of blue folders = 22
Number of brown folders
= 22 + 6
= 28
Number of red folders
= 2 x 28
= 56
Cost of blue folders
= 22 x 1.90
= $41.80
Cost of red folders
= 56 x 3.90
= $218.40
Cost of brown folders
= 313.40 - 218.40 - 41.80
= $53.20
Cost of 1 brown folder
= 53.20 ÷ 28
= $1.90
Answer(s) (a) 22; (b) $1.90
