Read a binomial mode and an expected number of qualifying samples

Samples, each of 12 articles, are taken at random from a large consignment in which 25% of articles are defective.

Find the number of defective articles which is most likely to occur in a single sample, and find the probability of obtaining this number.

If 100 samples of 12 articles are to be examined, calculate the number of samples in which you would expect to find 4 or more defective articles.