Question 197931
Let G be the number of girls and B be the number of boys
{{{TotalStudents = Girls + Boys}}}
{{{T = G + B}}}

You are told
{{{G/4 = T/6}}}
{{{G/4 = (G+B)/6}}}
{{{6G = 4(G+B)}}}
{{{6G = 4G + 4B}}}
{{{2G = 4B}}}
{{{2/4 = B/G}}}
So the ratio of boys to girls is "1 boy for every 2 girls" or {{{1/2}}}