Creating matrix with binomial distribution

Hi, I am new to R and this environment but use R at university as part of statistics. In one of our problems they tell us that there are 50 people in 30 different country's each listening to 15 songs and rating the songs with a thumbs-up or thumbs-down and they give us that the probability of getting a thumbs-up is 65%. The first part of the question I could do where they asked to define the random variable and give its distribution (Bin(15, 0.65)) and then determine expected value and variance. the second part it were I am struggling they say we have to generate a matrix with 30 samples of size 50 using the distribution in part 1, then calculate the mean of each sample and draw a histogram of mean values calculated. Help or guidance in this matter would be appreciated.Thanks