How many kg of pure salt must be added to 30kg of 2% solution of salt and water to increase it to 10% solution ? Choose one:  A) 3/5  B) 4/3  C) 5/7  D) 2/3  E) 8/3
Amount of salt in 30kg solution = [(20/100)*30]kg=0.6kg   Let x kg of pure salt be added   Then , (0.6+x)/(30+x)=10/100   60+100x=300+10x   90x=240   x=8/3.   Answer is 8/3.
<result>E</result>
How many kg of pure salt must be added to 30kg of 2% solution of salt and water to increase it to 10% solution ?