Pamela spent $220 on some pens, notebooks and staplers. The number of pens she bought was ¹₂ the number of notebooks. The number of staplers she bought was ³₅ the number of notebooks. The ratio of the amount of money she spent on the pens, notebooks and staplers was 5 : 8 : 9. The notebooks were sold at 5 for $10. Find the price of 1 pen.

Amount spent
Pens	Notebooks	Staplers	Total
5 u	8 u	9 u	$220

Total amount that Pamela spent on pens, notebooks and staplers
= 5 u + 8 u + 9 u
= 22 u

22 u = 220

1 u = 220 ÷ 22 = 10

Amount that Pamela spent on notebooks
= 8 u
= 8 x 10
= $80

Number of sets of notebooks of 5 bought
= 80 ÷ 10
= 8

Number of notebooks that Pamela bought
= 8 x 5
= 40

Number of items bought
Pens	Notebooks	Staplers	Total
1x5	2x5
	5x2	3x2
5 p	10 p	6 p	21 p

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

Number of notebooks that Pamela bought = 10 p

10 p = 40

1 p = 40 ÷ 10 = 4

Number of pens that Pamela bought
= 5 p
= 5 x 4
= 20

Amount that Pamela spent on pens
= 5 u
= 5 x 10
= $50

Price of 1 pen
= 50 ÷ 20
= $2.50

Answer(s): $2.50