Find the mean, median, and mode. Plz help me it’s a test

Aparallel system functions whenever at least one of its components works. consider a parallel system of n components, and suppose each component works independently with probability 0.5. find the conditional probability that component n works given that the system is working

How do you solve a question like this?

Calculate the missing value. round the answer to on decimal place. start with 70, increase it by 21%, and end up with