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

[Q]: Problem: a certain store sold pens for $ 0.35 each and pencils for $ 0.25 each . if a customer purchased both pens and pencils from the store for a total of $ 1.80 , what total number of pens and pencils did the customer purchase ? 
Options: a ) 6 , b ) 9 , c ) 10 , d ) 11 , e ) 12
[A]: a


[Q]: Problem: the ratio of two quantities is 4 : 3 . if each of the quantities is decreased by 8 , their ratio changes to 3 : 1 then the smallest number is ? 
Options: a ) 5.2 , b ) 6.9 , c ) 9.6 , d ) 7.8 , e ) 4.7
[A]: c


[Q]: Problem: the compound ratio of 1 : 3 , 1 : 2 and 1 : 5 ? 
Options: a ) 1 : 30 , b ) 1 : 5 , c ) 1 : 7 , d ) 1 : 1 , e ) 1 : 6
[A]:
a