Total number of addressable block are 2^16 , Total number of blocks needed for directory = 4 , so maximum file size in blocks is 2^16 = 65536 . Total memory for storing 2k file records of 32 bits each = 2048*32/8 = 8192 bytes. Total number of blocks need to store directory is 4 , so 4 * BlockSize = 8192 , BlockSize = 2048 bytes. Total size of largest file in blocks(MB) = 65536*2048/2^20 = 128 MB