$(10$pts$)$ A $8-$way set associative cache has the same data size and block size as the direct$-$mapped cache in Question #$6.$

$($a$)$ How many sets are there in the cache?

$($b$)$ How is a $64-$bit memory address divided into tag, set index, and byte offset? Calculate the number of bits for each field.

$($c$)$ Calculate the total size of the cache.