1) A mixture contains alcohol and water in the ratio 4 : 3. If 5 litres of water is added to the mixture, the ratio becomes 4 : 5. Find the quantity of alcohol in the given mixture. A) 9 B) 10 C) 12 D) 14 E) 16 Answer: Option BExplanation:Let the quantity of alcohol and water be 4x litres and 3x litres respectively. Then, 4x3x+5 =45 ⇔20x=4(3x+5) ⇔8x=20 ⇔x=2.5Quantity of alcohol =(4×2.5) litres = 10 litres.