min and max range of an 8 bit integer in 1's ,2's complement

Question

what is the min and max range  of an 8 bit integer  when it is stored in

a)sign magnitude form

b)1's complement form

c)2's complement form

Comments

a) -127 to +127

b) -127 to +127

c) -128 to +127

Answer 1

Range of n bit binary number

A] unsigned number --> $0$ to $2^n-1$

B] signed number [1 bit for sign]

     a) sign & magnitude --> $(-2^{n-1}+1)$ to $(2^{n-1}-1)$

     b) 1's compliment --> $(-2^{n-1}+1)$ to $(2^{n-1}-1)$

     c) 2's compliment --> $(-2^{n-1})$ to $(-2^{n-1}-1)$