SOLUTION: On the first day of school, the percentage of boys in a particular class is 60%. During the school year,six girls move away, and are replaced in the class by six boys, this makes t

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Question 477900: On the first day of school, the percentage of boys in a particular class is 60%. During the school year,six girls move away, and are replaced in the class by six boys, this makes the class roster 75% boys. Find the number of boys and girls in the class on the first day.

I am completely lost on this one.
Answer by mangopeeler07(462)   (Show Source): You can put this solution on YOUR website!

Set B for the number of boys on the first day. Set G for the number of girls.
so (A for all), where (sixty percent).


Six girls move


and six boys come


And now the boys make up 75% of the class


Using and , plug in .6A for B:


Subtract .6A from both sides:


Now divide both sides by .15


So there were 40 kids in all on the first day. 60% of them were boys, so:


40-24=G


So on the first day of school, there were 24 boys and 16 girls.
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