[" B- "8" .Anugget of gold and quartz was found to contain "x" g of gold and "y" g of quartz and has density d.If the "],[" densitites of gold and quartz are "d" ,and "d_(2)" respectively then the correct relation is: "],[[" (A) "(x)/(d_(1))+(y)/(d_(2))=(x+y)/(d)," (B) "xd_(1)+yd_(2)=(x+y)d],[" (C) "(x)/(d_(2))+(y)/(d_(1))=(x+y)/(d)," (D) "(x+y)/(d)+(x)/(d_(1))+(x)/(d_(2))=0]]