UPSC CDS 2 2022 Math Paper

According to the question
Alcohol contained in first glass = 3/5
Water contained in first glass = 2/5
Alcohol contained in second glass = 4/5
Water contained in second glass = 1/5
Now, the ratio of alcohol and water in the third glass
⇒ (3/5 + 4/5) : (2/5 + 1/5)
⇒ (7/5 : 3/5)
⇒ 7 : 3
∴ The required ratio is 7 : 3