Question

In a classroom of 33 students, the ratio of boys to girls is 3:8. How many boys are in the class?
A:12, since 38 of the students are boys
B:11 , since 33 divided by 33 equals 11
C:9 , since 3/11 of the students are boys
D:You cannot tell because you do not know the fraction of the total number of students that are boys.

Answer 1

x=number of boys
y=number of girls.

We can suggest the following system of equations:
x+y=33
x/y=3/8

We solve this system of equations by substitution method.
x/y=3/8       ⇒x=3y/8

(3y/8)+y=33
least common multiple=8
3y+8y=33*8
11y=33*8
y=(33*8)/11
y=3*8
y=24

x+y=33
x+24=33
x=33-24
x=9

number of boys /total number of students=9/33=3/11

There are 9 boys and 24 girls in the class. 

Answer: C: 9. since 3/11 of the students are boys. 

Answer 2

the answer is 9

i'm only writing more because its making me or else i can't post this. I need the points badly! so... yeah... also thanks to the person who posted before me because i thought you were wrong until i read the step by step

hope you pass your Imagine Math lesson or whatever program you are doing!

good luck!

--- a weaboo who really wants to be an anime character, and is also in love with the show Yuri!!! on ICE