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Answer:

You may have noticed that 0111 1111 is one less than 1000 0000, which is 128. So 0111 1111 represents of 12710.

Further Famous Bit Patterns

Say that a number is represented with all ones on the right and all zeros on the left, like this: 0011 1111. To find the decimal equivalent, turn on the bit to the left of the left-most one and then turn off all other bits. Compute the decimal equivalent of the resulting pattern and then subtract one.

For example, the equivalent of 0011 1111 is 0100 0000 - 1. The decimal value corresponding to the single "on" bit is 64 and 64 - 1 = 63.

Here is another table of bit patterns (regarded as representing positive integers) and their decimal equivalent. See if you can notice something interesting.

BinaryDecimalNotes
0000 0001 1    
0000 0010 2     1 × 2
0000 0100 4     2 × 2
0000 1000 8     4 × 2
0000 0011 3    
0000 0110 6     3 × 2
0000 1100 12     6 × 2
0001 1000 24     12 × 2
0000 0111 7    
0000 1110 14     7 × 2
0001 1100 28     14 × 2
0011 0000 56     28 × 2

 

QUESTION 4:

The bit pattern 0011 0010 represents 5010. What bit pattern represents 10010?