Question

12 is 25% of what number?percent ×whole=part

Answer 1

If we know that 12 is 25% of x (unknown) 
And we want to find x we can just multiply 12 by 4, because
12 is 25%: so
12 = $\frac{25}{100}$
12 = $\frac{1}{4}$   / *4
48 = 1 - 1 means 100% of x, so just x
The result is 48

Answer 2

$25\% \ of \ x= 12 \\\\ \frac{25}{100}*x=12 \\\\ \frac{1}{4}=\frac{12}{x} \\\\ x=\frac{4*12}{1} \\\\ \boxed{x=48}$