Two vessels contains equal number of mixtures milk and water in the ratio 5:2 and 6:1. Both the mixtures are now mixed thoroughly. Find the ratio of milk to water in the new mixture so obtained?	Choose the correct choice from the following choices:
A) 1 : 3
B) 9 : 13
C) 5 : 11
D) 11 : 3
E) 15 : 4

Rationale: "the ratio of milk and water in the new vessel is = ( 5 / 7 + 6 / 7 ) : ( 2 / 7 + 1 / 7 ) = 11 / 7 : 3 / 7 = 11 : 3 answer is d"
Answer: D