Question 1121791
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The formal algebraic solution by the other tutor is fine.  But for me, the way to start the problem that makes it most clear what is being done is<br>
{{{0.97(10)+0.43(x) = 0.61(10+x)}}}<br>
But here is a method for solving this kind of problem that is much faster and easier, if you understand it.<br>
(1) The percentage of the final mixture (61%) is twice as close to 43% as it is to 97%:  61-43 = 18; 96-61 = 36.<br>
(2) Therefore the mixture needs to have twice as much of the 43% water as it has of the 97% water.<br>
(3) Since you have 10 cups of the 97% water ingredient, you need 20 cups of the 43% water ingredient.