Can someone help with this problem?

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

Is a positive integer raised to a negative power always positive

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply