Elyse spent $132 on some notebooks, files and pens. The number of notebooks she bought was ¹₂ the number of files. The number of pens she bought was ¹₅ the number of files. The ratio of the amount of money she spent on the notebooks, files and pens was 9 : 7 : 6. The files were sold at 5 for $7. Find the price of 1 notebook.

Amount spent
Notebooks	Files	Pens	Total
9 u	7 u	6 u	$132

Total amount that Elyse spent on notebooks, files and pens
= 9 u + 7 u + 6 u
= 22 u

22 u = 132

1 u = 132 ÷ 22 = 6

Amount that Elyse spent on files
= 7 u
= 7 x 6
= $42

Number of sets of files of 5 bought
= 42 ÷ 7
= 6

Number of files that Elyse bought
= 6 x 5
= 30

Number of items bought
Notebooks	Files	Pens	Total
1x5	2x5
	5x2	1x2
5 p	10 p	2 p	17 p

The number of files bought is repeated.  Make the number of files bought is the same.  LCM of 2 and 5 is 10.

Number of files that Elyse bought = 10 p

10 p = 30

1 p = 30 ÷ 10 = 3

Number of notebooks that Elyse bought
= 5 p
= 5 x 3
= 15

Amount that Elyse spent on notebooks
= 9 u
= 9 x 6
= $54

Price of 1 notebook
= 54 ÷ 15
= $3.60

Answer(s): $3.60