can someone help me solve this problem

Question

Ahmed needs to produce 5000 milliliters of 50% alcohol solution. At his disposal he has 80% alcohol solution and 40% alcohol solution. How much of each does he need in order to produce his desired solution

Answer 1

Let x = number of ml of 80% solution

Then 5000 - x = number of ml of 40% solution

Then, 0.80x + 0.40(5000 - x) = 0.50(5000)

0.80x + 2000 - 0.40x = 2500

0.40x = 500

x = 1250 ml

Use 1250 ml of 80% solution and 3750 ml of 40% solution