Question

Two equal glasses filled with mixtures of alcohol and water in the proportions of \(2:1\) and \(1:1\) respectively were emptied into a third glass. What is the proportion of alcohol and water in the third glass?

• A. 5 : 7
• B. 7 : 5
• C. 7 : 6
• D. 6 : 7

Hint:

When mixing two solutions of equal volume, simply take the average contribution of each component. Always assume an easy number like 100 or 300 ml for quick calculations.