Please help me with this question.

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

If the discriminant if a quadratic equation is 4 which statement describes the roots?

Find the maximum value of p= 4x + 5y subject to the following constraints :