Answer : 4. "7:3"
Explanation :

Answer: D) 7:3 Explanation: Ratio of Milk and water in a vessel A is 4 : 1   Ratio of Milk and water in a vessel B is 3 : 2   Ratio of only milk in vessel A = 4 : 5   Ratio of only milk in vessel B = 3 : 5   Let 'x' be the quantity of milk in vessel C   Now as equal quantities are taken out from both vessels A & B   => 4/5     :     3/5               x   3/5-x          x - 4/5   => 35-xx-45 = 11 (equal quantities)   => x = 7/10   Therefore, quantity of milk in vessel C  = 7   => Water quantity = 10 - 7 = 3   Hence the ratio of milk & water in vessel 3 is 7 : 3