HELP ME!

12 is 15% of what number?

Let the number =N, then:

15%N = 12

0.15N = 12    divide both sides by 0.15

N =12 / 0.15

N = 80

12 is 15% of 80.

Setup a proportion. Setting up a proportion allows the calculation to be simpler arithmetically:

$\frac{12}{x}=\frac{15}{100}$Simplify the 15/100 by dividing the numerator and denominator by the GCF, 5.

$\frac{12}{x}=\frac{3}{20}$Cross multiply and solve for x

$12*20=3x$Simplify the left hand side of the equation

$240=3x$ Divide by 3 on bioth sides to isolate x

$80=x$