Question

A class contains 13 boys and 17 girls. of the girls, 25% have blond hair. what percentage of the class are blonds

Answer 1

14.2% of the class are blonds.

Explanation:

We have been given that a class contains 13 boys and 17 girls. of the girls, 25% have blond hair.

First of all, we will find 25% of 17.

`(25)/(100)\cdot 17=0.25\cdot 17=4.25`

Now, we will find 4.25 is what percent of total students (13+17=30).

Let 4.25 be x percent of 30. We can represent this information in an equation as:

`(x)/(100)\cdot 30=4.25`

Now, let us solve for x.

`(x)/(100)\cdot 30\cdot (100)/(30)=4.25\cdot (100)/(30)`

`x=(425)/(30)`

`x=14.166`

`x\approx 14.2`

Therefore, 14.2 percentage of the class are blonds.

Answer 2

For this case, we first look for the number of blonde girls.
We have then:

`(25/100) * (17) = 4.25`
We are now looking for the percentage of the class with blonde hair.
For this, we make the following rule of three:
30 --------------> 100%
4.25 -----------> x
From here, we clear the value of x.
We have then:

`x = (4.25 / 30) * (100) x = 14.2%`
Answer:
14.2% of the class are blonds