Question 797513
Proportions can be written as fractions
{{{(Total Number of Girls)/(Total Number of Students)=(3/8)}}}
But you only have number of boys, so you can find the proportion of boys in class by subtracting {{{1-(3/8)}}}. This means the ratio of boys to students is {{{5/8}}}. Since you can only have boys or girls the remainder of the class must be boys which is why {{{1-(3/8)}}} is true.

{{{(Total Number of Boys)/(Total Number of Students)=(5/8)}}}
{{{10/(Total Number of Students)=(5/8)}}}
{{{80=5(Total Number of Students)}}}
{{{Total Number of Students=16}}}