Find the value of MP! Need help!

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

A. 127 cm^2 b. 144.5 cm^2 c. 172 cm^2 d. 50 cm^2

Explain how you can find the missing fraction in 3 4/5 / (blank) 2 5/7. then find the missing fraction.