An alloy weighing 26 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 correct choice from the following answers.
A) 6	B) 9	C) 12	D) 34	E) 48

Rationale: in 24 ounces , gold is 26 * ( 70 / 100 ) = 18.2 ounces . now we add x ounces of pure gold to make it 90 % gold . so 18.2 + x = ( 24 + x ) * 90 / 100 = > x = 34 . answer is d .
Answer: D