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

[EX Q]: Problem: in the third grade of windblown school there are 90 students , one third of them failed the math test and 1 / 6 failed that literature test . at least how many students failed both tests ? 
Options: a ) 0 . , b ) 6 . , c ) 8 . , d ) 10 . , e ) 12 .
[EX A]: a

[EX Q]: Problem: the ratio of the arithmetic mean of two numbers to one of the numbers is 5 : 8 . what is the ratio of the smaller number to the larger number ? 
Options: a ) 1 : 8 , b ) 1 : 6 , c ) 1 : 5 , d ) 1 : 4 , e ) 1 : 3
[EX A]: d

[EX Q]: Problem: at an international conference , “ red ” world countries and “ blue ” world countries are the only participants . the ratio of “ red ” world participants to “ blue ” world participants is 7 : 3 . if one - third of “ red ” world participants are left - handed and two - thirds of “ blue ” world participants are left - handed , then what is the fraction of the participants who are left - handed ? 
Options: a ) 45 / 21 , b ) 46 / 2 , c ) 13 / 30 , d ) 23 / 6 , e ) 4 / 6
[EX A]:
c