A) 2 : 1
B) 1 : 2
C) 4 : 1
D) 1 : 4
Correct Answer: B
$ \therefore $ Part of milk in first vessel $ =\frac{3}{5} $ $ ( by\frac{a}{a+b} ) $ and ratio of milk and water in second vessel $ =7:3 $
$ \therefore $ Part of milk in second vessel $ =\frac{7}{10} $ and new mixture ratio $ =2:1 $ By alligation rule,
$ \therefore $ Required ratio $ =\frac{1}{30}:\frac{1}{15}=1:2 $