The number of red folders is four times the number of purple folders. The number of purple folders is 6 more than the number of orange folders. The total number of folders is 108. The cost of each red folder is $2.70 and the cost of each orange folder is $2.80. The total cost of all the folders is $275.80.
- Find the number of orange folders.
- Find the cost of a purple folder.
(a)
Number of orange folders = 1 u
Number of purple folders = 1 u + 6
Number of red folders
= 4(1 u + 6)
= 4 u + 24
Total of number of folders
= 1 u + 1 u + 6 + 4 u + 24
= 6 u + 30
6 u + 30 = 108
6 u = 108 - 30
6 u = 78
1 u = 78 ÷ 6 = 13
Number of orange folders
= 1 u
= 13
(b)
Number of orange folders = 13
Number of purple folders
= 13 + 6
= 19
Number of red folders
= 4 x 19
= 76
Cost of orange folders
= 13 x 2.80
= $36.40
Cost of red folders
= 76 x 2.70
= $205.20
Cost of purple folders
= 275.80 - 205.20 - 36.40
= $34.20
Cost of 1 purple folder
= 34.20 ÷ 19
= $1.80
Answer(s) (a) 13; (b) $1.80
