instruction:
In this task, you need to provide the correct option for a given problem from the provided options.
question:
Problem: in a certain alphabet , 16 letters contain a dot and a straight line . 30 letters contain a straight line but do not contain a dot . if that alphabet has 50 letters , all of which contain either a dot or a straight line or both , how many letters contain a dot but do not contain a straight line ? 
Options: a ) 4 , b ) 8 , c ) 12 , d ) 16 , e ) 20
answer:
a


question:
Problem: if there are 10 apples and 20 oranges , what is the ratio of apples to oranges ? 
Options: a ) 10 : 20 , b ) 2 : 4 , c ) 1 : 2 , d ) 4 : 8 , e ) it can not be determined from the information given
answer:
c


question:
Problem: what is the greatest positive integer n such that 3 ^ n is a factor of 36 ^ 300 ? 
Options: a ) 100 , b ) 200 , c ) 300 , d ) 600 , e ) 900
answer:

d