2022 · Q17
Two glasses of equal volume are filled with a mixture of alcohol and water in the ratio 3 : 2 and 4 : 1, respectively. These glasses are emptied into a third glass. What is the ratio of alcohol and water in the third glass?
Elementary MathematicsRatio and Proportion
- A5 : 4
- B7 : 2
- C7 : 3
- D7 : 4
Explanation
With each glass of volume V: alcohol = V(3/5+4/5) = 7V/5 and water = V(2/5+1/5) = 3V/5, so the ratio is 7:3. (Simply adding the ratios 3+4 : 2+1 happens to work only because the volumes are equal; the safe method uses per-glass fractions.) The keyed option is C.