Answer: 20 pounds of walnuts should be mixed with 40 pounds of peanuts.
Step-by-step explanation:
Let x represent the number of pounds of walnuts that should be in the mixture.
Let y represent the number of pounds of peanuts that should be in the mixture.
The number of pounds of the mixture to be made is 60. This means that
x + y = 60
Walnuts cost $3.60 per pound and peanuts cost $2.70 per pound. The mixture will sell for $3.00 per pound. It means that the total cost of the mixture is 3 × 60 = $180. The expression would be
3.6x + 2.7y = 180- - - - - - - - - - - - -1
Substituting x = 60 - y into equation 1, it becomes
3.6(60 - y) + 2.7y = 180
216 - 3.6y + 2.7y = 180
- 3.6y + 2.7y = 180 - 216
- 0.9y = - 36
y = - 36/ - 0.9
y = 40
x = 60 - y = 60 - 40
x = 20