How many kg of pure salt must be added to 100kg of 10% solution of salt and water to increase it to a 35% solution?	Answers.
A) A)6.7	B) B)38.5	C) C)9.6	D) D)12.5	E) E)7.9
Amount salt in 100kg solution = 10*100/100= 
<gadget id="calculator">10*100/100</gadget>
<output>10</output>
10 kg   Let x kg of pure salt be added   then(10+x)/(100+x)=35/100   200+20x=700+7x   13x = 500   x = 28.5   Answer is 38.5
<result>B</result>
How many kg of pure salt must be added to 100kg of 10% solution of salt and water to increase it to a 35% solution?