A school bought pens, each costing $1, and pencils, each costing $0.5. The cost of the whole purchase was $220. How many pens and pencils were purchased if there were 80 more pencils than pens?

200 pencils and 120 pens

Step-by-step explanation:

Let the number of pencils be x while pens be y.

Considering the cost of whole purchase then, we get the equation

0.5x+y=220

Considering the number of items bought, then the equation is

x-y=80

Adding the two equations then we have

1.5x=300

x=300/1.5=200

Consideeing that x-y=80 and x is 200 then

200-y=80

y=200-80=120

Therefore, the pencils were 200 and pens 120 pieces

the least common denominatore of 7 and 2 is 9

step-by-step explanation:

7+2=9