How many pounds of nails costing $7 per pound must be mixed with 6 pounds of nails costing $3 per pound to yield a mixture costing $4 per pound?
2 pounds.
2.5 pounds.
3 pounds.
3.5 pounds.
Detailed Explanation
Let x = number of nails costing $7 per pound. The total cost of the mixture equals the sum of the cost for each type of nail or M = A + B, where A = 7x, B = 3(6), and M = 4(6 + x). Substitute the known values into the equation. 4(6 + x) = 7x + 18.
24 + 4x = 7x + 18
24 – 18 = 7x – 4x
3x = 6
x = 2
Take more free practice tests for other ASVAB topics with our ASVAB practice test now!