Question

Jim paid $3.99 for a 14-ounce bag of cookies. What was the
unit cost per pound?

Answer 1

$3.99 / (14/16 lb) = (8/7)*($3.99) = $4.56/lb

Answer 2

More than one way to skin a cat. Proportions come up a lot and this can be solved as one.

State the relationship you need verbally.

"3.99 is to 14, as x is to 16"

Then set up a proportion.

3.99 x
---- = ----
14 16

Cross-multiply, giving:

14x = 16(3.99)

Divide both sides by 14, giving:

x = (16/14)3.99

Reduce:

x = (8/7)3.99

Finally, you need to pull out your calculator.

x = 31.92/7
x = 4.56


That is the cost per 16 ounces: that is, per pound.