#### Answer

72

#### Work Step by Step

Let the unknown number be $x$. One-eighth of this number is $\frac{1}{8}x$, one-sixth of this number is $\frac{1}{6}x$, and three-fourth of this number is $\frac{3}{4}x$. Since we know that the sum of 1/8 and 1/6 of this number is subtracted from 3/4 of this number to get 33, we obtain:
$\frac{3}{4}x-(\frac{1}{8}x+\frac{1}{6}x)=33$
$\frac{3}{4}x-(\frac{3x+4x}{24})=33$
$\frac{3}{4}x-(\frac{7x}{24})=33$
$\frac{3x(6)-7x}{24}=33$
$\frac{18x-7x}{24}=33$
$11x=792$
$x=\frac{792}{11}=72$
Therefore, the unknown number is 72.