Question

Let's say that a 14-ounce cup of coffee is 20 percent milk. If you add 7 ounces of coffee, what is the percentage of milk in the new mixture? (Round your answer to two decimal places

Answer 1

still around

Answer 2

the original amount of milk in the 14oz of coffee is 20% of 14, or 14*(0.2)= 2.8
that means that there are 2.8oz of milk in the 14oz of coffee.
Once the 7oz extra are added, to make 21oz of coffee, the original amount of milk remains, 2.8oz. Bear in mind that the percentage of either substance will be
\(
\cfrac{substance}{total}
\), so for milk that'd be \(\cfrac{2.8}{14} originaly\) and \( \cfrac{2.8}{7+14}\) for the added 7oz cup. so \(\cfrac{2.8}{21}\) is your answer :)