Okay, here we have this:
Considering the provided information, we are going to calculate the requested number, so we obtain the following:
Then from the given information we have the following equation (we will take the unknown number as x):
(x/4)-3=0
Let's solve for x:
(x/4)-3=0
(x/4)-3+3=0+3
x/4=3
x/4*4=3*4
x=12
Finally we obtain that the unknown number is 12.