Suppose that a process scheduling algorithm favors those processes that have used the least processor time in the recent past. Why will this algorithm favour /IO- bound processes, but not starve CPU-bound processes?

It will favor the I/O-bound programs because of the relatively short CPU burst request by them; however, the CPU-bound programs will not starve because the I/O- bound programs will relinquish the CPU relatively often to do their I/O.