What decimal number does the bit pattern 01101111 represent

What decimal number does the bit pattern 01101111 represent if it is a:

two\'s complement integer?

Solution

two\'s complement integer is :01101111

by converting it into decimal number it will -145

explanation:

0 1 1 0 1 1 1 1
-1 0 0 1 0 0 0 0
+ 1
--------------------
1 0 0 1 0 0 0 1

so it give 91base 16 converting it to decimal it gives 9*16+1=144+1=145

as it negative number it is -145