Question 265590
Let x pounds of peanuts and y pounds of raisins be used.
Total is x+y = 3  ...(1) 
Also, the cost of peanuts is $2.00 per pound and the cost of raisins is $3.50 per pound.
The resulting blend costs $3 per pound
So,      2x+3.5y = 3*3
         2x+3.5y = 9    ...(2)
(1)*2=>  2x+2y = 6      ...(3)
(2)-(3)=> 1.5y = 3
          y = 3/(1.5)
          y = 2
(1)=>     x+2 = 3
          x = 3-2 
          x = 1