The number of purple folders is twice 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 123. The cost of each purple folder is $2.70 and the cost of each green folder is $2.90. The total cost of all the folders is $334.30.
- 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 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 green folders
= 1 u
= 27
(b)
Number of green folders = 27
Number of blue folders
= 27 + 5
= 32
Number of purple folders
= 2 x 32
= 64
Cost of green folders
= 27 x 2.90
= $78.30
Cost of purple folders
= 64 x 2.70
= $172.80
Cost of blue folders
= 334.30 - 172.80 - 78.30
= $83.20
Cost of 1 blue folder
= 83.20 ÷ 32
= $2.60
Answer(s) (a) 27; (b) $2.60
