Let the number of pens to be bought = x
Let the number of pencils to be bought = y
Cost of 1 pen = $0.35
Cost of 1 pencil = $ 0.20
Number of pens and pencils needed = at least 300
Money to be spent = no more than $80
Inequalities become =
[tex]x+y\geq300[/tex] ...... (1)
[tex]0.35x+0.20y\leq80[/tex] ....(2)