A solution consists of acid and water in the ratio 7:5. If 6 litres of water is added, the new ratio becomes 7:6. What is the original quantity of acid in the solution?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 42 litres.
Let the original quantity of acid be 7x litres and water be 5x litres
So, 7x/(5x + 6) = 7/6
⇒ 42x = 35x + 42
⇒ 7x = 42
⇒ x = 6
Original quantity of acid = 7x = 7 × 6 = 42 litres