
Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion 
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November 25th, 2011, 04:48 AM  #1 
Newbie Joined: Nov 2011 Posts: 3 Thanks: 0  Formula help?
364 students in a school, 204 are boys and 160 were girls. a) How many % Boys were there in that school. I don't need the answer, just the formula to get too the answer. 
November 25th, 2011, 06:22 AM  #2 
Senior Member Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,193 Thanks: 504 Math Focus: Calculus/ODEs  Re: Formula help?
Let B be the number of boys and T be the total number of students. Then the percentage of boys is given by: 
November 25th, 2011, 02:21 PM  #3 
Newbie Joined: Nov 2011 Posts: 3 Thanks: 0  Re: Formula help?
Ok thank you, i'm having a math exam soon, I don't think I really am prepared for it.

November 25th, 2011, 02:47 PM  #4 
Senior Member Joined: Apr 2011 From: USA Posts: 782 Thanks: 1  Re: Formula help?
Any time you want to know what percent one thing is of another thing, you divide the first by the second. Percentages are essentially a proportion (based on 100). So you have 204 boys and 364 students, so you're wanting to know what proportion 204 is out of the 364 total, so you divide in that order. (That will give the decimal version of it, so you still have to move the decimal to the right twice to write it in percent form. Which is an unfortunate confusion for people with percentages.) You can learn it as base, rate, part. The "of" is the base. (The total students. What percent OF the total students is the boys?) If you're taking something and splitting it down into parts, the base is the whole thing. The boys and the girls in this case are parts. You're solving for the rate. Solving for base and rate are always divisions, with the part always coming first: part/base or part/rate. If you have base and rate, and just want to know what's x% of some number, that's a multiplication  you can't put the part first if you're solving for it , so then you know it's not a division. 
November 26th, 2011, 12:21 PM  #5 
Newbie Joined: Nov 2011 Posts: 3 Thanks: 0  Re: Formula help?
Thank's for the explaination. Really helped!


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