<PRE><B>Question 422600</B>
grape juice claims that the drink contains 10 percent grape juice.
 How much pure grape juice would need to be added to 5 quarts of drink to obtain
 a mixture containing 40 percent grape juice
:
Let x = amt of pure grape juice required to accomplish this
:
.10(5) + 1x = .40(x + 5)
.5 + x = .4x + 2
x - .4x = 2 - .5
.6x = 1.5
x = {{{1.5/.6}}}
x = 2.5 qts of pure grape juice required
:
:
Confirm this solution
.1(5) + 2.5 + .4(2.5+5)
.5 + 2.5 = .4(7.5)
3 = 3, a good equation </PRE>