Question

$70\%$ of the students in a school are boys and the number of girls is $504$ find the number of boys in the school.

Answer 1

% of boys + % of girls = $100$

70 + % of girls = $100$

% of girls = $30$

and,

number of girls $=\frac{\%ofgirls}{100}\times$ total students

$504=\frac{30}{100}\times$ total students

$\Rightarrow$ total students $=1680$

$\therefore$ number of boys $=$ total students $-$ no. of girls

$=1680-540$

$=1176$