In this task, you need to provide the correct option for a given problem on probability from the provided options.
Example: Problem: in a throw of a coin find the probability of getting a tail ? 
Options: a ) 1 / 2 , b ) 1 / 3 , c ) 1 / 4 , d ) 2 / 5 , e ) 2 / 7
Example solution: a
Example explanation: "s = { h , t } e = { t } p ( e ) = 1 / 2 answer is a"

Problem: Problem: a box contains 20 electric bulbs , out of which 4 are defective . two bulbs are chosen at random form this box . the probability that at least one of these is defective is : 
Options: a ) 8 / 19 , b ) 7 / 19 , c ) 10 / 19 , d ) 20 / 19 , e ) 22 / 19

Solution: b