Question

An online retailer sells two packages of protein bars.

Answer 1

In order to find the price per bar, we divide the price by the amount of bars.  For the first one:

15.37/10 = $1.54 per bar

The second package:

15.35/12 = $1.28 per bar.

The 10-pack costs $1.54 per bar and the 12-pack costs $1.28 per bar.  The 12-pack has the better price per bar.

Now, let's look at the price per ounce.  We do this in a similar way.  We find the total amount of ounces in the package, and divide the price by the number of ounces.

In the first package, we multiply 10*2.1=21.  We have 21 ounces in the first package.  Now we divide 15.37/21.  In the first package, we have 0.73 dollars per ounce.

Now, let's look at the second package.  We start by multiplying 1.4*12=16.8.  There are 16.8 ounces in the package.  Now, we divide 15.35/16.8=0.91.  So, in the second package, we have 0.91 dollars per ounce.

The cost per ounce of the 10-pack is $0.73 and the cost per ounce of the 12-pack is $0.91.  The first package has the better price per ounce.

The better explanation is the second one, because I prefer the lower price per ounce, I think that the 1st pack is the better buy.