SOLUTION: Mary is 7 years older than her brother and her brother is 10 years younger than her cousin. The sum of the ages is 47. How ald are they?

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: Mary is 7 years older than her brother and her brother is 10 years younger than her cousin. The sum of the ages is 47. How ald are they?       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1116244: Mary is 7 years older than her brother and her brother is 10 years younger than her cousin. The sum of the ages is 47. How ald are they?
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
m, Mary
b, Brother
c, Cousin
system%28m=b%2B7%2Cb=c-10%2Cm%2Bb%2Bc=47%29

The first and second equations can be written in terms of b; and then these used to rewrite the last equation all in ONE variable.


system%28m=b%2B7%2Cc=b%2B10%29

The age sum equation: %28b%2B7%29%2Bb%2B%28b%2B10%29=47
Solve and use it to evaluate m and c.