In the page table in Fig. 3-10 (below), the last column contains one-bit number known as present/absent bit for each page mapping. What is the purpose of the bit? Outgoing physical address (24580) 15 000 0 14 000 0 13 000 0 12 000 0 10 000 0 9 1011 8000 0 7 0000 60000 5 011 1 4100 1 3 000 1 2 1101 1 001 1 0 0101 12-bit offset copied directly from input to output Page table 110 Present/ absent bit Virtual page 2 is used as an index into the Incoming virtual address (8196) page table 001l0lololololololol00100