An alloy weighing 20 ounces is 70 percent gold. How many ounces of pure gold must be added to create an alloy that is 90 percent gold?  Choose the most appropriate option:
A) 6 B) 9 C) 12 D) 76 E) 48
In 24 ounces, gold is 20 * (70/100)= 
<gadget id="calculator">20 * (70/100)</gadget>
<output>14</output>
14 ounces. Now we add x ounces of pure gold to make it 90% gold.   So 14 + x= (24 + x)* 90/100 =&gt; x =76.   Answer is 76.
<result>D</result>
An alloy weighing 20 ounces is 70 percent gold. How many ounces of pure gold must be added to create an alloy that is 90 percent gold?