3. [25] Consider a processor with a 42 bit virtual address, 16GB of physical memory, 4KB page size, and page table entry (PTE) size of 4 bytes. a) [5] How many page table entries are required for a single level page table? b) [5] How much physical memory is required to store them? c) [5] If instead, a three level hierarchical page table is used with the index at each level the same number of bits, how much total space is used if the tables are fully populated and physically resident? d) [5] If the multi-level page tables are only populated when virtual space is allocated, what are the minimum space requirements for a process? e) [5] How much memory can the minimum sized process have before increasing the number of page tables?