Boolean Algebra fundementals

Question

A disjunction A OR B truth table has A , B , and A OR B but mine has A ,B C, with A or B or C could some please explain this

Answer 1

It's really all the same thing.

$$\begin{array}{c|c|cc} A & B & A\vee B \\ \hline 1 & 1 & 1 \\ 1 & 0 & 1 \\ 0 & 1 & 1 \\ 0 & 0 & 0 & \star\end{array} \qquad \begin{array}{c|c|c|cc} A & B & C & A\vee B\vee C \\ \hline 1 & 1 & 1 & 1 \\ 1 & 1 & 0 & 1 \\ 1 & 0 & 1 & 1 \\ 1 & 0 & 0 & 1 \\ 0 & 1 & 1 & 1 \\ 0 & 1 & 0 & 1 \\ 0 & 0 & 1 & 1 \\ 0 & 0 & 0 & 0 & \star\end{array}$$

etc. The truth value of $A\vee B\vee C$ is $1$ whenever any of the $A$, $B$ or $C$ is $1$. It is only zero if all of them are zero (in the rows marked $\star$). Replace $1$ with $T$ and $0$ with $F$ to your liking.