A chemical supply company has 60 liters of a 20% HNO3 solution. How many liters of pure undiluted HNO3 must the chemists add so that the resultant solution is a 50% solution? Select: A) 12 B) 15 C) 20 D) 24 E) 36
60 liters of a 20% HNO3 solution means HNO3 = 12 liters in 60 liters of the solution.   Now, let x be the pure HNO3 added.   As per question,   12 + x = 50% of (60 + x)   or x =36. Hence, 36
<result>E</result>
A chemical supply company has 60 liters of a 20% HNO3 solution. How many liters of pure undiluted HNO3 must the chemists add so that the resultant solution is a 50% solution?