How many kg of pure salt must be added to 30kg of 2% solution of salt and water to increase it to a 10% solution?
Given : 2% salt must be added to 30 kg solution
Then amount of salt in 30 kg solution =2100×30=0.6 kg
Let x kg of pure salt added
∴0.6+x30+x=10100
⇒60+100x=300+10x
⇒100x−10x=300−60
⇒90x=240
⇒x=24090=83
Then 83=223 kg salt added in solution