The distributive property is a simplification rule that does not change the value of an expression. Nothing need be done to the other side of the equation.
q = -4(3+x)
q = -4*3 -4*x . . . . . the -4 is distributed. The right side has not changed value.
Set this up as a ratio putting inches on top and feet on bottom. Then your first ratio would be 1/25 since 1 inch is the same as 25 feet. In between them goes an equals sign and the the other ratio has an x on top (because inches is what we are looking for) and the 1500 on the bottom. Cross multiply to solve for x:
1(1500) = x(25). Divide both sides by 25 to get 60
The probability is 8 out of 20 or 40 percent