Question

A pound of nails cost $2. A pound of screws cost $6. How many pounds of nails are needed for a 5–pound mixture that costs $3.60 per pound?

Answer 1

the options are 1,2,3,4

Answer 2

Let the number of pounds of nails be x and screws be y.
x+y=5
x=5-y-(1)
2x+6y=5*3.6
2(5-y)+6y=18
10-2y+6y=18
10+4y=18
4y=18-10
4y=8
y=8/2
y=2
Nw substitute the value of y in (1) to find x.