Quick questions on Two's complement integers explained: H2 Computing

To form the negative of any two's complement number: invert every bit, then add one. The same procedure undoes itself, so it converts $+x$ to $-x$ and $-x$ back to $+x$.

For $n$ bits the range is asymmetric:

Signed overflow happens when adding two numbers of the same sign produces a result of the opposite sign. Equivalently, overflow occurred if the carry into the sign bit differs from the carry out of it. Adding numbers of opposite signs can never overflow.

Represent $-1$ in 8-bit two's complement. [2 marks]

State the range of a 16-bit two's complement integer. [1 mark]

Does adding $01111111$ and $00000001$ (8-bit signed) overflow? Explain. [2 marks]