Acid and water are mixed in a vessel A in the ratio of 5 : 2 and in the vessel B in the ratio 8 : 5. In what proportion should quantities be taken out from the two vessels so as to form a mixture in which acid and water will be in the ratio of 9 : 4?

• A. 7 : 2
• B. 2 : 7
• C. 7 : 4
• D. 2 : 3