Answer:
10 pounds.
Step-by-step explanation:
Let x pounds be the amount of mixed nuts we require.
Amount of peanuts in this mix = 0.70x pounds. Amount of peanuts in the 20% mix = 0.20*15 = 3 pounds.
So we have the equation:-
0.70 x + 3 = 0.40(x + 15)
0.70 x + 3 = 0.40(x + 15)
0.70x + 3 = 0.40x + 6
0.70x - 0.40x = 6 - 3
0.30x = 3
x = 10.
