in a binomial experiment the probability of success is 0.06. what is the probability of two successes in 7 trials?

in a binomial experiment the probability of success is 0.06. what is the probability of two successes in 7 trials?Twenty percent of the student in a classs of 100 are planning to go to graduate school. the standard deviation of the binomial distribution is?x is a random variable with the probability function: f(x) = x/6 for x=1,2,3 the expected value of x is/