The sum of three numbers in base two is 11101. If the first two numbers are 1011 and 1101 find the

Question

third number?

Answer 1

Just add and subtract in base 2

x + 1011 + 1101 = 11101
x + 11000 = 11101
= 101

or , copping out and changing to base 10

1011₂ = 11₁₀
1101₂ = 13₁₀

11101₂ = 29₁₀
y + 11 + 13 = 29
y = 5
and 5₁₀ = 101₂ , as above