Question

How much salt should Ilya add to 810g of water to make 10% solution? How much solution will he make? Ilya should add __g of salt and he will make __g of solution

Answer 1

90 g of water should be added and he will make 900 g of solution.

Explanation:

Let x g be the amount of salt Ilya add to 810g of water to make 10% solution. Then 810+x g is the amount of new solution. Thus,

810+x - 100%,

x - 10%.

Mathematically,

`(810+x)/(x)=(100)/(10),\\ \\10(810+x)=100x,\\ \\8100+10x=100x,\\ \\100x-10x=8100,\\ \\90x=8100,\\ \\x=(8100)/(90)=90\ g.`

So 90 g of water should be added and he will make 810+90=900 g of solution.