instruction:
In this task, you need to provide the correct option for a given problem on probability from the provided options.
question:
Problem: what is the probability of randomly selecting an arrangement of the letters of the word ` ` mediterranean ' ' in which the first letter is e and the last letter is r ? 
Options: a ) 1 / 13 , b ) 1 / 20 , c ) 1 / 26 , d ) 1 / 50 , e ) 1 / 100
answer:
c


question:
Problem: the probability that a number selected at random from the first 50 natural numbers is a composite number is 
Options: a ) 17 / 26 , b ) 17 / 25 , c ) 17 / 20 , d ) 17 / 22 , e ) 17 / 21
answer:
b


question:
Problem: what is the probability of getting exactly 4 heads in a single throw of five fair coins ? 
Options: a ) 1 / 4 , b ) 3 / 8 , c ) 3 / 16 , d ) 5 / 32 , e ) 7 / 32
answer:

d