The number of purple folders is twice the number of red folders. The number of red folders is 5 more than the number of brown folders. The total number of folders is 123. The cost of each purple folder is $4.30 and the cost of each brown folder is $2.20. The total cost of all the folders is $369.80.
- Find the number of brown folders.
- Find the cost of a red folder.
(a)
Number of brown folders = 1 u
Number of red folders = 1 u + 5
Number of purple folders
= 2(1 u + 5)
= 2 u + 10
Total of number of folders
= 1 u + 1 u + 5 + 2 u + 10
= 4 u + 15
4 u + 15 = 123
4 u = 123 - 15
4 u = 108
1 u = 108 ÷ 4 = 27
Number of brown folders
= 1 u
= 27
(b)
Number of brown folders = 27
Number of red folders
= 27 + 5
= 32
Number of purple folders
= 2 x 32
= 64
Cost of brown folders
= 27 x 2.20
= $59.40
Cost of purple folders
= 64 x 4.30
= $275.20
Cost of red folders
= 369.80 - 275.20 - 59.40
= $35.20
Cost of 1 red folder
= 35.20 ÷ 32
= $1.10
Answer(s) (a) 27; (b) $1.10
