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40% of my class is girls. 30% of girls play soccer. 24 girls play soccer. How many boys in class?

 Apr 5, 2020
 #1
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If 3/10 of 2/5x = 24, then 6/50x = 24. x = the class. Then, we can multiply both sides by 50/6 and get that x = 200. Using that 2/5 of the class is girls, 3/5 of the class is boys. So, 200 * 3/5 = 120 boys.

 Apr 5, 2020
 #2
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0

24 girls= 30% of girls

8 girls= 10% of girls

80 girls=100% of girls

80 people: 40 % of class

20 people: 10% of class

200 people: 100% of class

200 people in the class, 80 girls, so 120 boys.

 

smileysmileysmiley

 Apr 5, 2020
 #3
avatar+52 
+1

Good job! I never thought of that approach to the question. 

 #4
avatar+46 
+1

We know the amount of girls that play soccer and the percentage, so set them equal

30% of the girls in the class is 24 girls.

You can create a proportion to find the total amount of girls in the class

out of       3 girls who play soccer       =  24 girls

there are 10 girls in the total class     =  80 girls

There are 80 girls in the class.

To find the number of BOYS, create another proportion to find the students.

4 girls       =  80 girls

10 students    =  200 students

There are 200 students in the class.

Now subtract the amount of girls to find the boys

200-80=120 boys.

 

I wonder... How many boys play soccer??

 

XD

 Apr 5, 2020
edited by derpiiXD  Apr 5, 2020
 #5
avatar+1956 
+1
 Apr 5, 2020

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