A zinc-copper alloy with 2 kg of pure zinc would contain 90% of zinc. The alloy with 1 kg of 90% zinc alloy contains 84% of zinc. Calculate the weight and percentage of zinc in the zinc-copper alloy.	Choose the correct choice from the following choices:  A) 2.4 kg or 80%  B) 1.4 kg or 88%  C) 1.9 kg or 94.2%  D) 7.4 kg or 18%  E) 1.4 kg or 60%
Right Answer Explanation:   x : 2   y : 100   90   10 : 90 – y   (90-y)/2 = 10/x = ………..(1)   In the second case,   x 1   y 90   84   6 84-y   Therefore (84-y)/1 = 6/x ………..(2)   Dividing (1) and (2)   =   180 – 3y =840 – 10y   7y = 660   y = 94.2   x = 20/(90-80) = 20/10= 
<gadget id="calculator">20/10</gadget>
<output>2</output>
2 kg   Quantity of zinc in x= 94.2% of x   = 0.942 2   =1.9 kg   Weight and percentage of zinc is 1.9 kg or 94.2%   1.9 kg or 94.2%
<result>C</result>
A zinc-copper alloy with 2 kg of pure zinc would contain 90% of zinc. The alloy with 1 kg of 90% zinc alloy contains 84% of zinc. Calculate the weight and percentage of zinc in the zinc-copper alloy.