The number of green folders is twice the number of yellow folders. The number of yellow folders is 10 more than the number of red folders. The total number of folders is 114. The cost of each green folder is $4.20 and the cost of each red folder is $2.60. The total cost of all the folders is $386.30.
- Find the number of red folders.
- Find the cost of a yellow folder.
(a)
Number of red folders = 1 u
Number of yellow folders = 1 u + 10
Number of green folders
= 2(1 u + 10)
= 2 u + 20
Total of number of folders
= 1 u + 1 u + 10 + 2 u + 20
= 4 u + 30
4 u + 30 = 114
4 u = 114 - 30
4 u = 84
1 u = 84 ÷ 4 = 21
Number of red folders
= 1 u
= 21
(b)
Number of red folders = 21
Number of yellow folders
= 21 + 10
= 31
Number of green folders
= 2 x 31
= 62
Cost of red folders
= 21 x 2.60
= $54.60
Cost of green folders
= 62 x 4.20
= $260.40
Cost of yellow folders
= 386.30 - 260.40 - 54.60
= $71.30
Cost of 1 yellow folder
= 71.30 ÷ 31
= $2.30
Answer(s) (a) 21; (b) $2.30
