Question 62407
You and I arrived at the same equation to solve but I think that you made a mistake in solving the equation.

Let x=Number of lbs of nuts
Then 7-x=Number of lbs of fruit
Now we know that the amount of $ collected from selling the nuts(x)($16) and fruit(7-x)($3) separately would have to equal the amount of $ collected from selling the final mixture (7)($12).  Thus, our equation to solve is:

$16x+(7-x)($3)=7($12) Simplifying, we get:
16x+21-3x=84 or
13x=63
x=4 and 11/13 lbs of nuts
7-x=7-4 and 11/13 = 2 and 2/13 lbs of fruit

Hope this helps-----ptaylor