$20.$ When adding two n$-$bit $2$s complement numbers, overflow will NOT occur, if

a$.$ Both operands have different sign bits

b$.$ Both operands have same sign bits, and the sign bit of the result is also same

c$.$ Carry$-$in bits to MSBs are same as the Carry$-$out bit from the MSB

d$.$ All of the above

$21.$ Consider the following operations on $4-$bit two$$s complement numbers. Which will give

overflow?

a$.1110+1111$

b$.0111+0001$

c$.1111+0111$

d$.0110+0001$

$22.$ In Java programming language, the char data type is a single $16-$bit Unicode character and

implemented as $16-$bit unsigned integer. It has a minimum value of $\text{'}\backslash$u$0000\text{'}($or $0)$ and a

maximum value of $\text{'}\backslash$uffff$\text{'}($or $65,535$ inclusive$).$ What will be printed when the following code

snippet is executed?

a$.65535$

b$.-1$

c$.0$

d$.$ Run time error

$23.$ In Java programming language the data type byte is implemented as $8-$bit two$$s complement

integer. What will be printed when the following code snippet is executed?

a$.128$

b$.-128$

c$.0$

d$.$ Run time error

$24.$ In Java programming language the data type int is represented as $32-$bit two$$s complement

integer. What will be printed when the following code snippet is executed $(0$x means Hex

number$)?$ Why?

a$.0$x$10000000,$ because $0$xF $+1=0$x$10$

b$.0,$ because $0$xFFFFFFFF will be $-1$

c$.-1,$ because $0$xFFFFFFFF will be $0$

d$.0$xFFFFFFFG$,$ because $0$xF $+1=0$xG