Answer:
8 pounds
Explanation:
Let a, b, c represent the number of pounds of nuts in the first, second, and third boxes, respectively. We can write the equations ...
a = b +c -6 . . . . . first box has 6# fewer than the total of the others
b = a +c -10 . . . . second box has 10# fewer than the total of the others
Substituting the second equation into the first, we find ...
a = (a +c -10) +c -6
0 = 2c -16 . . . . subtract a
0 = c -8 . . . . . . divide by 2
8 = c . . . . . . . . . add 8
There are 8 pounds of nuts in the third box.