An urn contains 30 red balls and 70 green balls. What is the probability of getting exactly k red balls in a sample of size 20 if the sampling is done with replacement? Assume \(0\leq k \leq 20\).

An urn consists of 30 red balls and 70 green balls. What is the probability of getting exactly kk red balls in a sample of size 20 if the sampling is done without replacement?