In this task, you need to provide the correct option for a given problem from the provided options.

Problem: in what ratio must tea at rs . 65 per kg be mixed with tea at rs . 70 per kg so that the mixture must be worth rs . 6 per kg ? 
Options: a ) 1 : 1 , b ) 3 : 2 , c ) 4 : 3 , d ) 5 : 3 , e ) none
a

Problem: jo ' s collection contains us , indian and british stamps . if the ratio of us to indian stamps is 4 to 2 and the ratio of indian to british stamps is 5 to 1 , what is the ratio of us to british stamps ? 
Options: a ) 5 : 1 , b ) 10 : 5 , c ) 15 : 2 , d ) 20 : 2 , e ) 25 : 2
d

Problem: if log 2 = 0.3010 and log 3 = 0.4771 , the values of log 5 512 is 
Options: a ) 3.879 , b ) 3.875 , c ) 3.872 , d ) 3.828 , e ) 3.192

b