Help please, I really need it to move on.

Given a(-12,5) and b(12,29) find the point that divides the line segment ab three-eighths of the way from a to b

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

Which of those sequences is a geometric sequence