How many kg of pure salt must be added to 100kg of 10% solution of salt and water to increase it to a 20% solution? Choices.
A) 6.7	B) 1.3	C) 9.6	D) 12.5	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)=20/100   100+10x=200+2x   8x = 100   x = 12.5   Answer is 12.5
<result>D</result>
How many kg of pure salt must be added to 100kg of 10% solution of salt and water to increase it to a 20% solution?