If after 200 grams of water were added to the 30%-solution of alcohol, the strength of the solution decreased by one-third, how much of the 30%-solution was used?
Choose the correct choice from the following:
A) 100 grams
B) 220 grams
C) 250 grams
D) 350 grams
E) 400 grams
The 30% alcohol solution decreases by 1/3 once the 200 grams of water is added so  200/.1= 
<gadget id="calculator"> 200/.1</gadget>
<output>2_000</output>
2000*.05% (2/3 of 30%) is 100 grams, thus answer is 100 grams.
<result>A</result>
If after 200 grams of water were added to the 30%-solution of alcohol, the strength of the solution decreased by one-third, how much of the 30%-solution was used?