Calculate 3/7 of 28: Finding Female Students in a Class

Question

In a ninth grade class, there are 28 students, $\frac{3}{7}$ of whom are female.

How many females are in the class?

00:00 How many girls are in the class?

00:03 The given ratio of girls

00:07 Multiply this ratio by total students to find number of girls

00:11 Break down 28 into factors 7 and 4

00:25 Reduce what's possible

00:28 Calculate the multiplication

00:32 And this is the solution to the question

Let's write the following exercise, we'll multiply the fraction by the number of students:

$\frac{3}{7}\times28$

Let's multiply the numerator by 28:

$\frac{3\times28}{7}$

Let's solve the exercise in the numerator, we'll break down 28 into a smaller multiplication exercise:

$\frac{3\times7\times4}{7}=$

Let's reduce the 7 in the numerator and denominator of the fraction and we'll get:

$3\times4=12$

$12$