Question

If pens cost 9 cents each, what equation could be written to calculate the cost, c, of any number of pens, p?

Answer 1

The total cost (in dollars) of p pens is C = 0.09 p

Explanation:

The cost of each pen = 9 cents

Now, 1 cent = $0.01 cents

⇒ 9 cents = $0.09

So, the cost of 1 pen = $0.09

The number of pens purchased= p

Let the total cost of p pens = c

Also, the cost of p pens = p x ( Cost of 1 pen) = p ( $0.09) = 0.09 p

or, C = 0.09 p

Hence the total cost (in dollars) of p pens is C = 0.09 p.