Two vessels contains equal number of mixtures milk and water in the ratio 4:1 and 7:3. Both the mixtures are now mixed thoroughly. Find the ratio of milk to water in the new mixture so obtained?  Choose the correct answer:
A) 2 : 1
B) 4 : 1
C) 3 : 1
D) 2 : 3
E) 4 : 3

Rationale: the ratio of milk and water in the new vessel is = ( 4 / 5 + 7 / 10 ) : ( 1 / 5 + 3 / 10 ) = 3 / 2 : 1 / 2 = 3 : 1 answer is c
Answer: C