forecasting

Hi john sir how r u..plz help me with the following questions..

1..A company accountant is analysing the reject rates achieved by 100 factory operatives working in identical conditions. Rejects rates, y% are found to be related to months of experience, x, by this regression equation: y= 20-0.25x.( The correlation coefficient was r = -0.9)

Using the equation, the predicted reject rate for an operative with 12 months experience is closest to

A..17 percent
b..19 percent
c..20 percent
d..23 percent

John sir ..the thing which is confusing me more is corelation coeffienct in ths question…ans is 17 percent but how?