Consider the RAID$5$ system depicted in the diagram below:

a$)(3)$ Each strip or block contains data and each parity block is computed as the XOR of the strips within that stripe $($or row$).$ Assume that disk $3$ fails and is later replaced with a new disk. Once disk $3$ is replaced, it must be repopulated by writing all of the required data and parity. Show how Strip $2$ on the new disk $3$ can be computed.

Strip$2=\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

b$)(3)$ If all five disks are operating properly, can strip$6$ and strip$14$ be written in parallel on this system? Explain why or why not.