Question

in a class of 42 students the number of boys is 2/5 of the girls . find the number of boys and girls

Answer 1

in plain and short, we simply divide 42 by (2+5) and distribute accordingly.

$\bf \cfrac{boys}{girls}\qquad 2:5\qquad \cfrac{2\cdot \frac{42}{2+5}}{5\cdot \frac{42}{2+5}}\implies \cfrac{2\cdot 6}{5\cdot 6}\implies \cfrac{12}{30}$