A shopkeeper bought x pens for $21.
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.
c(x) = 2100/x
s(x) = c(x)+8 = 2100/x + 8
extra credit: how much money did he make on the sales?
a) To find the cost, in cents, of each pen, we can divide the total cost by the number of pens. In this case, the shopkeeper bought x pens for $21. Since there are 100 cents in a dollar, we can convert the total cost to cents by multiplying it by 100. Therefore, the expression to find the cost, in cents, of each pen is:
Cost of each pen = (Total cost in cents) / (Number of pens)
Cost of each pen = (21 * 100) / x
Cost of each pen = 2100 / x
b) To find the selling price of each pen, we start with the cost of each pen and add 8 cents. The shopkeeper sold each of the remaining pens at 8 cents more than he paid for it. Thus, the expression for the selling price of each pen is:
Selling price of each pen = Cost of each pen + 8 cents
Selling price of each pen = 2100 / x + 8 cents