Question

numa escola de 900 alunos,42% são rapazes. Calcule o número de rapazes

Answer 1

regra de três

$\large\boxed{\begin{array}{lr} \frac{900}{x} = \frac{100\%}{42\%} \\ \\ 100x = 900 \times 42 \\ 100x = 37800 \\ x = 37800/100 \\ \boxed{378} \\ \\ resposta \: → \: 378\end{array}}$

Answer 2

$\sf\dfrac{900}{x}=\dfrac{100\%}{42\%}$

$\sf100x=37800$

$\sf x=\dfrac{37800}{100}$

$\boxed{\boxed{\sf x=378}}$