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

Input: Consider Input: Problem: a bag contains 10 black and 20 white balls . one ball is drawn at random . what is the probability that the ball drawn is white ? 
Options: a ) 1 / 2 , b ) 3 / 4 , c ) 2 / 3 , d ) 1 / 5 , e ) 3 / 7

Output: c


Input: Consider Input: Problem: a certain junior class has 1,000 students and a certain senior class has 600 students . among these students , there are 60 siblings pairs , each consisting of 1 junior and 1 senior . if 1 student is to be selected at random from each class , what is the probability that the 2 students selected at will be a sibling pair ? 
Options: a ) 3 / 40,000 , b ) 1 / 10,000 , c ) 9 / 2,000 , d ) 1 / 60 , e ) 1 / 15

Output: b


Input: Consider Input: Problem: there are 24 students in a class . in how many different ways can a committee of 3 students be formed ? 
Options: a ) 1250 , b ) 1800 , c ) 2024 , d ) 3256 , e ) 2864


Output: c