SOLUTION: There are 15 girls in your class this year. That is a 15% increase from last year. a. Write a proportion to solve for the number of girls in the class last year. b. Sol

Algebra ->  Percentages: Solvers, Trainers, Word Problems and pie charts -> SOLUTION: There are 15 girls in your class this year. That is a 15% increase from last year. a. Write a proportion to solve for the number of girls in the class last year. b. Sol      Log On


   

Question 1143184: There are 15 girls in your class this year. That is a 15% increase from last year.
a. Write a proportion to solve for the number of girls in the class last year.


b. Solve the proportion in part (a).


Answer by ikleyn(52803) About Me  (Show Source):
You can put this solution on YOUR website!
.
Let x = the number of girls in the class last year.


Then from the condition, you have this equation


    %2815-x%29%2Fx = 0.15.


Solve it for x


    15 - x = 0.15x


    15 = 0.15x + x

    15 = 1.15x

    x  = 15%2F1.15 = 13.043.


Round to the closest integer  x= 13.    ANSWER


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Usually, the problems of this kind are formulated to get an integer number as the answer without rounding . . .

Or, if rounding is necessary, then the condition says about it directly and explicitly.