Question 257219
This is a mixture problem. Here is a table based on the given information:
NUTS . . . . . . . . . $ . . . . . . . . . . pounds . . . . . . . . . . . . $pounds
Walnuts . . . . . . . 4 . . . . . . . . . . .10 . . . . . . . . . . . . . . . . .40
Cashew . . . . . . . 7 . . . . . . . . . . . .X . . . . . . . . . . . . . . . . .7X
MIXTURE . . . . . .5.50 . . . .. . . . .. (X-10) . . . . . .. . .. . . .. 5.50X - 55
In the last column, the first two terms add to the last as
{{{40+7X = 5.50X + 55}}}
Solving for X, we get
{{{1.50X = 15}}}
X = 10 pounds