A shopkeeper bought x pens for $21.

Question

a) write down an expression, in terms of x, for the cost, in cents, of each pen
b) the shopkeeper gave 2 pens to his sons and sold each of the remaining pens at 8 cents more than he paid for it. Write down an expression, in terms of x, for the selling price of each pen.

Answer 1

c(x) = 2100/x
s(x) = c(x)+8 = 2100/x + 8

extra credit: how much money did he make on the sales?