Question 979106
{{{"0.50%"=50/100=0.5}}}
{{{"0.40%"=40/100=0.4}}}
{{{"0.46%"=46/100=0.46}}}
{{{1200}}}= number of boys in the school
{{{0.5*1200=600}}}= number of boys that paid school fee
{{{x}}}= number of girls in the school
{{{0.4*x}}}= number of girls that paid school fee
So,
{{{1200+x}}}= number of students (boys and girls) in the school
{{{0.46*(1200+x)}}}= number of students that paid school fee
That must be what we get when we add
the number of boys that paid school fee, plus
the number of girls that paid school fee, so
{{{0.46*(1200+x)=600+0.4*x}}}
{{{0.46*1200+0.46*x=600+0.4*x}}}
{{{552+0.46*x=600+0.4*x}}}
{{{552+0.46*x-0.4*x-552=600+0.4*x-0.4*x-552}}}
{{{(0.46-0.4)*x=600-552}}}
{{{0.06*x=48}}}
{{{x=48/0.06}}}
{{{highlight(x=800)}}}