Number of sets in cache = v. The question gives a sequencing for the cache lines. For set 0, the cache lines are numbered 0, 1, …, k-1. Now for set 1, the cache lines are numbered k, k+1,… k+k-1 and so on. So, main memory block j will be mapped to set (j mod v), which will be any one of the cache lines from (j mod v) * k to (j mod v) * k + (k-1). (Associativity plays no role in mapping- k-way associativity means there are k spaces for a block and hence reduces the chances of replacement.