Out of 40 students in billy's class, 18 are girls. what percent of the students are boys?

First, how many boys are in the Billy's class room? We know there are a total of 40 students and 18 girls. That means 22 are boys because 40 - 18 = 22.

The 40 students represents 100% of the class room.

= 1
To convert into a percentage, multiply by 100.

1 * 100 = 100%

We can use the same reasoning to get the percentage of the boys.

= 0.55

Multiply by 100.

0.55 * 100 = 55%

So, 55% of the students are boys.