Jean spent $57 on some pens, markers and files. The number of pens she bought was ³₄ the number of markers. The number of files she bought was ³₅ the number of markers. The ratio of the amount of money she spent on the pens, markers and files was 7 : 8 : 4. The markers were sold at 5 for $6. Find the price of 1 pen.

Amount spent
Pens	Markers	Files	Total
7 u	8 u	4 u	$57

Total amount that Jean spent on pens, markers and files
= 7 u + 8 u + 4 u
= 19 u

19 u = 57

1 u = 57 ÷ 19 = 3

Amount that Jean spent on markers
= 8 u
= 8 x 3
= $24

Number of sets of markers of 5 bought
= 24 ÷ 6
= 4

Number of markers that Jean bought
= 4 x 5
= 20

Number of items bought
Pens	Markers	Files	Total
3x5	4x5
	5x4	3x4
15 p	20 p	12 p	47 p

The number of markers bought is repeated.  Make the number of markers bought is the same.  LCM of 4 and 5 is 20.

Number of markers that Jean bought = 20 p

20 p = 20

1 p = 20 ÷ 20 = 1

Number of pens that Jean bought
= 15 p
= 15 x 1
= 15

Amount that Jean spent on pens
= 7 u
= 7 x 3
= $21

Price of 1 pen
= 21 ÷ 15
= $1.40

Answer(s): $1.40