Question

If one store sells 12 pens for $9.00 and another sells 10 pens for $7.80, which is the better deal?

Answer 1

9.00/12 = 0.75 per pen
7.80/10 = 0.78 per pen

the better deal (the cheapest one) is 12 pens for $ 9

Answer 2

12 pens for $9.00

Explanation:

To calculate what is the better deal in both stores you just have to calculate the price per unit that each one is offering, in this case the first one sells 12 pens for $9.00 you just divide the price by the number of units:

`Price-per-unit=(total)/(numberofunits)\\Price-per-unit=(9)/(12)\\Price-per-unit=.75`

We know that in the first store each pen costs $.75, now we calculate the price per unite in the second store:

`Price-per-unit=(total)/(numberofunits)\\Price-per-unit=(7.8)/(10)\\Price-per-unit=.78`

So in the second store the price per each pen is $.78, this means that the better deal is the first store since each pen costs $.03 less than in the second one.