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

[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: find the number of zeroes at the end of 50 ! 
Options: a ) 10 , b ) 11 , c ) 12 , d ) 13 , e ) 14
[EX A]: c

[EX Q]: Problem: of the diplomats attending a summit conference , 30 speak french , 32 do not speak russian , and 20 % of the diplomats speak neither french nor russian . if 10 % of the diplomats speak both languages , then how many diplomats attended the conference ? 
Options: a ) 20 , b ) 96 , c ) 108 , d ) 120 , e ) 150
[EX A]:
a