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

[EX Q]: Problem: a man invests some money partly in 15 % stock at 105 and partly in 8 % stock at 40 . to obtain equal dividends from both , he must invest the money in the ratio : 
Options: a ) 3 : 4 , b ) 3 : 5 , c ) 7 : 5 , d ) 16 : 15 , e ) none
[EX A]: c

[EX Q]: Problem: a can contains a mixture of liquids a and b is the ratio 7 : 5 . when 9 litres of mixture are drawn off and the can is filled with b , the ratio of a and b becomes 7 : 9 . how many liter e of liquid a was contained by the can initially ? 
Options: a ) 10 , b ) 20 , c ) 21 , d ) 25 , e ) 27
[EX A]: c

[EX Q]: Problem: 7 machines at a certain factory operate at the same constant rate . if 6 of these machines , operating simultaneously , take 42 hours to fill a certain production order , how many fewer hours does it take all 7 machines , operating simultaneously , to fill the same production order ? 
Options: a ) 3 , b ) 4 , c ) 5 , d ) 6 , e ) 7
[EX A]:
d