Question

A pharmacist is to prepare 30 milliliters of a solution with a drug concentration of 2 mg/mL. To do so,
he will mix a solution with a drug concentration of 7 mg/mL with grape-flavored syrup. If 𝑥 represents
the number of milliliters of grape-flavored syrup needed, find the value of 𝑥.

Answer 1

make sure the amount of drug adds up:

7(30-x) + 0x = 2(30)

Answer 2

Drug needed in 30ml at 2mg/ml =2mg*30 which is 60mg. Therefore number of ml at 7mg/ml =60mg/7mg. So the answer is 8.5ml of grape syrup. Conclussion: The value of ₹₹ is 8.5