Question 1050874
 In science class, 

let boys be {{{b}}} and girls {{{g}}}

if there are {{{25}}}% more girls than boys, then we have: 
since {{{25}}}%={{{(25/100)=1/4}}}, we have

{{{g=b+(1/4)b}}}.....eq.1

if {{{3}}} girls leave , we have {{{g-3}}}

then the number of boys is equal to the number of girls:{{{g-3=b}}}......eq.2

from {{{g-3=b}}}......eq.2 we have {{{g=b+3}}}......eq.2a

since eq1 and eq2a have same left sides, equal right sides and solve for {{{b}}}


{{{b+(1/4)b=b+3}}}....both sides multiply by {{{4}}}

{{{4b+b=4b+12}}}

{{{4b+b-4b=12}}}

{{{b=12}}}

now find {{{a}}}

{{{g=b+3}}}......eq.2a
{{{g=12+3}}}
{{{g=15}}}

so, there is {{{15}}} girls and {{{12}}} boys