Question 118464
Let's say that Scott gets x cents for his allowance.  We know he spent {{{x/9}}} cents on the newspaper, {{{2x/5}}} cents on the snack, and he has 220 cents remaining.  Assuming no additional purchases or expenditures,  these three amounts must add up to his total allowance, or:


{{{(x/9)+(2x/5)+220=x}}}


{{{(5x/45)+(18x/45)-(45x/45)=-220}}}


{{{-22x/45=-220}}}


{{{x/45=10}}}


{{{x=450}}} cents, or $4.50.


Check your answer:


One-ninth of $4.50 is $0.50.  Two-fifths of $4.50 is $1.80.


$0.50 + $1.80 = $2.30 and $4.50 - $2.30 = $2.20.