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

Problem: a meeting has to be conducted with 5 managers . find the number of ways in which the managers may be selected from among 8 managers , if there are 2 managers who refuse to attend the meeting together . 
Options: a ) 36 , b ) 40 , c ) 45 , d ) 51 , e ) 56
a

Problem: there are 22 students in a class . in how many different ways can a committee of 3 students be formed ? 
Options: a ) 1180 , b ) 1320 , c ) 1540 , d ) 1760 , e ) 1920
c

Problem: the probability that a number selected at random from the first 100 natural numbers is a composite number is ? 
Options: a ) 2 / 3 , b ) 3 / 5 , c ) 3 / 4 , d ) 3 / 2 , e ) 5 / 2

d