Answer:
Ok, suppose that a man earns X, and a woman earns Y.
if X is larger than Y, then:
((X - Y)/Y)*100% is the percentage by which the man earns more than the woman. (where Y represents the 100%)
Replacing the given values, we can see that:
X = $1200
Y = $1000
(($1200 - $1000)/$1000)*100% = ($200/$1200)*100% = 0.20*100% = 20%.
If you want the expression only in decimals then you need to ignore the 100% in the equation, and you will have:
(X - Y)/Y
($1200 - $1000)/$1000 = 0.20
This would work for any given values of X and Y.
Other way to see this is:
If the man earns X and the woman Y, then we can see at the quotient:
X/Y
For the previous values we have:
$1200/$1000 = 1.2
This means that the man earns 1.2 times what the woman earns.
If we multiply that by 100%, we have:
1.2*100% = 120%
So the man earns the 120%, which is the 100% that earns the woman plus a 20%, that is what we found before.
