The number of brown folders is four times the number of blue folders. The number of blue folders is 5 more than the number of green folders. The total number of folders is 109. The cost of each brown folder is $2.60 and the cost of each green folder is $2.40. The total cost of all the folders is $280.60.
- Find the number of green folders.
- Find the cost of a blue folder.
(a)
Number of green folders = 1 u
Number of blue folders = 1 u + 5
Number of brown folders
= 4(1 u + 5)
= 4 u + 20
Total of number of folders
= 1 u + 1 u + 5 + 4 u + 20
= 6 u + 25
6 u + 25 = 109
6 u = 109 - 25
6 u = 84
1 u = 84 ÷ 6 = 14
Number of green folders
= 1 u
= 14
(b)
Number of green folders = 14
Number of blue folders
= 14 + 5
= 19
Number of brown folders
= 4 x 19
= 76
Cost of green folders
= 14 x 2.40
= $33.60
Cost of brown folders
= 76 x 2.60
= $197.60
Cost of blue folders
= 280.60 - 197.60 - 33.60
= $49.40
Cost of 1 blue folder
= 49.40 ÷ 19
= $2.60
Answer(s) (a) 14; (b) $2.60