A pharmacist has 40% and 60iodine solutions on hand. How many liters of each iodine solutions will be required to produce 4 liters of a 50% iodine mixture

A pharmacist has 40% and 80% of iodine solutions on hand. How many liters of each iodine solution will be required to produce 4 liters of a 50% iodine mixture?

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Let x = liters of 40% iodine

then

4-x = liters of 80% iodine

Using algebra:

.40x +.80 (4-x) =.50 (4)

.40x + 3.20-.80x = 2

3.20-.40x = 2

x = 4 liters (40% iodine)

80% iodine:

4-x = 4-4 = 0 liters needed (80% iodine)