12 of the 30 students in Mrs. Smith's class are boys. What percent of the class is made up of girls?

60%

Step-by-step explanation:

First, find how many girls are in the class

There are 12 boys. The rest of the 30 students will be girls.

12+g=30

Subtract 12 from both sides to get the variable by itself

12-12+g=30-12

g=18

There are 18 girls.

Now, we have to find the percent.

To do this, divide the part: the girls, by the whole: the entire class

part/whole

girls/class

There are 18 girls, and 30 students in the whole class

18/30

0.6

Convert 0.6 to a percent by multiplying by 100, or moving the decimal place 2 spots to the right

0.6*100=60

0.6--> 6.0--> 60.

So, 60% of the class is made up of girls