What is the solution to y=x

Ineed i do not understand i'm only 8

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?

What effect would doubling all the dimensions of a triangular pyramid have on the volume of the pyramid? explain your reasoning.