An alloy weighing 20 ounces is 70 percent gold. How many ounces of pure gold must be added to create an alloy that is 70 percent gold?
Choose one
A) 6	B) 9	C) 12	D) 24	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)* 70/100 =&gt; x =9.   Answer is 9.
<result>B</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 70 percent gold?