The ratio of alcohol and water in three mixtures of alcohol and water is 3:2, 4:1, and 7:3. If equal quantities of the mixture are drawn and mixed, the concentration of alcohol in the resulting mixture will be? Choose the correct choice from the following choices
A) 65%  B) 70%  C) 75%  D) 80%  E) 90%
The ratios are given such that the sum of alcohol and water can be brought up to 10 for each mixture. (Since equal quantities are to be added)   For 3:2 lets take 6 parts alcohol and 4 parts water   For 4:1 lets take 8 parts alcohol and 2 parts water   For last since the sum is already 10, 7 parts alcohol and 3 parts water.   Mixing these three will give   6+8+7= 
<gadget id="calculator">  6+8+7</gadget>
<output>21</output>
21 units alcohol and  4+2+3= 
<gadget id="calculator"> 4+2+3</gadget>
<output>9</output>
9 units water   or, 21 units alcohol in 30 units of mixture     21/30 *100= 
<gadget id="calculator">  21/30 *100</gadget>
<output>70</output>
70%   Answer : 70%
<result>B</result>
The ratio of alcohol and water in three mixtures of alcohol and water is 3:2, 4:1, and 7:3. If equal quantities of the mixture are drawn and mixed, the concentration of alcohol in the resulting mixture will be?