Question

Katie’s baby sister drinks 4 ounces of apple juice with breakfast every morning. There was a full gallon of juice on the table. Katie had one pint.
How much is left for the baby?

Answer 1

Answer: 112 oz

First we have to work with the same units. According to the International System of Units (SI), the Liter (L) is the unit of measurement for liquids, however, we are going to use the ounce (oz) in this case, as it is the unit of measure of the juice that Katie's baby sister drinks.

In addition:

$1L=33.814 oz$    (1)

$1 pint=0.5L\approx 16 oz$   (2)

$1 gallon=3.78 L\approx 128 oz$    (3)

Knowing this, we can calculate  how much of apple juice is left for the baby after Katie drank a portion.

In order to do this, we have to substract the amount of juice Katie drank ($1 pint\approx 16 oz$) to the total amount of juice in the full gallon ($1 gallon\approx 128 oz$):

$128 oz-16 oz=112 oz$    

This means that there are $112 oz$ left for Katie’s baby sister.

In addition, taking into account the baby drinks  $4 oz$ each day, the $112 oz$ left are equivalent to approximately 28 days.