Question

What decimal value does the 8-bit binary number 10011110 have if it is on a computer using signed-magnitude representation?

Answer 1

1 0 0 1 1 1 1 0

0 * 2^{0} + 1 * 2^{1} + 1 * 2^{2} + 1 * 2^{3} + 1 * 2^{4}  + 0 * 2^{5} + 0 * 2^{6} = 30

The sign digit is a 1, so the entire number is negative, which gives -30.