How many pounds of nuts worth $1.10 per pound must be mixed with 36 pounds of candy worth $1.60 per pound to produce a party mix worth $1.50 per pound?

so... whatever "x" may be, we know that the whole mix will be "y" amount, thus x + 36 = y

and their total prices will also add up to 1.50y
thus  1.10x + 57.6 = 1.50y

thus     

solve for "x", to see how much nuts will be added

what about "y"? well x + 36 = y