Question

In a city of 56,000 people, there are 21,000 people under 25 years of age. What percent of the population is under 25 years of age?

Answer 1

Answer:

37.5

Step-by-step explanation:

So whenever you want to find "x" percent of a number, you just do: $\frac{x}{100} * n = \text{x\% of n}$. You're essentially converting the percentage to it's decimal value by dividing by 100.

Given this information, we're solving for x, instead of x% of n. In this case n = 56,000, and x% of 56,000 is 21,000

$\frac{x}{100} * 56000 = 2100$

Divide both sides by 56,000

$\frac{x}{100} = \frac{21,000}{56,000}$

Multiply both sides by 100

$x = 100(\frac{21,000}{56,000})$

Simplify:

$x = 37.5\%$

This can be generally thought of as:

$x=100(\frac{part}{whole})$

where part = partial amount, or how much is after finding what x% is of the whole amount, but in this case we know what it is, we just don't know what the "x" percent is.