Sterling silver is an alloy of silver that is 92.5% pure silver. If x grams
of sterling silver are mixed with y grams of an 88% silver alloy to produce a 91% silver
alloy, which of the following equations correctly relates x and y?
A. 0.075x+0.12y = 0
B. 0.015x -0.03y = 0
C. 0.925x +0.88y = 91
D. 0.925x +0.88y = 0.91xy