Will mark brainleist

Use the normal approximation to the binomial distribution to answer this question. fifteen percent of all students at a large university are absent on mondays. if a random sample of 12 names is called on a monday, what is the probability that four students are absent?

This is about circle theorems. someone asap : (

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25