Question

a certain shampoo is available in two sizes. a 13.5 ounce costs $2.19. a 29.2 ounce bottle costs $5.37. find the unit price for each size. then state which is the better buy based on the unit price. round to the nearest cent.

Answer 1

We can calculate the unit price of each option with the qoutient "price / volume". The one with the smaller unit price or price per unit of volume will be the better option.

The first option has a price of $2.19 and a volume of 13.5 oz, so we can calculate the unit price as:

$p_1=\frac{2.19\text{ \ }}{13.5\text{ oz}}\approx0.16\text{ \ /oz}$

The second option has a price of $5.37 and a volume of 29.2 oz, so the unit price is:

$p_2=\frac{5.37\text{ \ }}{29.2\text{ oz}}\approx0.18\text{ \ /oz}$

Answer:

The first option has a unit price of 0.16 $/oz while the second option has a unit price of 0.18 $/oz.

The first option is more economical in terms of price per volume, so it is the better option.