1. Consider demand paging. You are given the following reference string, page replacement policy and the number of frames available. Calculate the number of page faults in each case. A. ReferenceString:1234234235672342310 989108123 Algorithm: LRU
# of frames: 3
B. Reference String: Algorithm: Optimal
# of frames: 3
C. Reference String: Algorithm: LRU
# of frames: 2
D. Referencestring:1237841241541241281 011324171011 Algorithm: FIFO
# of frames: 3
E. Referencestring:1237841241541241281 011324171011 Algorithm: FIFO
# of frames: 4
To answer the question, write down the # of page fault, and also copy the reference string and circle all references that causes a page fault.
2. For the disk scheduling algorithm such as SCAN/c-SCAN, rotational delays are not used for optimization purpose. Suppose time require for one rotation is nearly the same as time to travel one track during seeking, suggest a way that you can further optimize one of the above algorithms.
3. For main memory allocation, nowadays virtually all systems uses demand paging, not contiguous allocation. However, for space allocation for files, contiguous allocation is still being used. Suggest two reasons why.

Formatting rows and columns is similar to cell formatting. in an openoffice calc spreadsheet, you can format data entered into rows and columns with the of the rows and columns options. you can insert rows and columns into, or delete rows and columns from, a spreadsheet. use the insert or delete rows and columns option on the insert tab. alternatively, select the row or column where you want new rows or columns to appear, right-click, and select insert only row or only column options. you can hide or show rows and columns in a spreadsheet. use the hide or show option on the format tab. for example, to hide a row, first select the row, then choose the insert tab, then select the row option, and then select hide. alternatively, you can select the row or columns, right-click, and select the hide or show option. you can adjust the height of rows and width of columns. select row and then select the height option on the format tab. similarly, select column, then select the width option on the format tab. alternatively, you can hold the mouse on the row and column divider, and drag the double arrow to the position. you can also use the autofit option on the table tab to resize rows and columns.