In a class, 60% of the students are girls. There are 18 girls in the class. How many boys are in the class? How many students are in the class?
Percentage of students that are girls in the class = 60%
Number of girls in the class = 18
Let us assume the total number of students in the class = x
Then
60% x = 18
(60/100) x = 18
6x/10 = 18
6x = 18 * 10
6x = 180
x = 180/6
= 30
So the total number of students in the class is 30.
Number of boys in the class = 30 - 18
= 12
So there are 12 boys in the class. I hope the procedure is simple enough for you to understand.
60% are girls, there are 18 girls in the class. How many boys?
This is quite easy to understand.
6x/10 = 18
6x/10 10 = 1810
6x = 180
x = 30
Now, thats the total, subtract by the girls.
30-18 = 12
Answer: 12