SOLUTION: A pharmacist is to prepare 15ml of special eye drops for a glaucoma patient. The eye-drop solution must have a 2% active ingredient, but the pharmacist only has a 10% and 1% soluti
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-> SOLUTION: A pharmacist is to prepare 15ml of special eye drops for a glaucoma patient. The eye-drop solution must have a 2% active ingredient, but the pharmacist only has a 10% and 1% soluti
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Question 1097756: A pharmacist is to prepare 15ml of special eye drops for a glaucoma patient. The eye-drop solution must have a 2% active ingredient, but the pharmacist only has a 10% and 1% solution in stock. Identify which one of the following shows the correct amount of each type of solution should be used to fill the prescription (2 decimal places required).
Totally lost.
Initially I thought:
0.1x +0.2 =15 0.01 y +0.2 =15
-.2 from both sdes
and then divided both sides by the decimal....giving a totally nonsense answer.
Totally lost. Answer by ikleyn(52778) (Show Source):
Let x be the amount (the volume in mL) of the 10% solution.
Then the amount of the 1% solution is (15-x) mL.
The balance equation is
0.1*x + 0.01*(15-x) = 0.02*15.
Multiply by 100 both sides and simplify:
10x + 15-x = 30 ====> 9x = 30-15 = 15 ====> x = = = 1.666 mL.
Answer. 1.666 mL of the 10% solution and 15 - 1.666 = 13.333 mL of the 1% solution.
Check. 1.666*0.1 + 13.333*0.01 = 0.3 = 0.02*15 mL ! Correct !
