He has 60 ounces of a 20% gold alloy and mixs it with 30% gold alloy to get a 24% gold alloy. How many ounces of the 30% gold alloy did he use?

Question

He has 60 ounces of a 20% gold alloy and mixs it with 30% gold alloy to get a 24% gold alloy. How many ounces of the 30% gold alloy did he use?

Answer 1

Let x = number of oz of 30% alloy

 

Gold content of first alloy = 0.20(60) = 12 oz

Gold content of second alloy = 0.30x

Gold content of end product = 0.24(x+60)

 

So, 12 + 0.30x = 0.24(x+60)

 

      12 + 0.30x = 0.24x + 14.4

 

             0.06x = 2.4

 

                   x = 40 oz