Question

A basket of laundry is being separated. Divide 48 pieces into 2 clothing groups so the ratio is 1 to 3

Answer 1

$\bf 48\qquad 1:3\qquad \cfrac{1}{3}\qquad \qquad \cfrac{1\cdot \frac{48}{1+3}}{3\cdot \frac{48}{1+3}}\implies \cfrac{1\cdot 12}{3\cdot 12}\implies \cfrac{12}{36}$

btw, don't put the shirts in the same bundle as the socks, you may end up with an unwanted perfume.