Truth Tables with Three or More Variables

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Subsection 2.3.3 Truth Tables with Three or More Variables

In the previous section, we saw examples of:

One-variable truth tables:

p	¬p
T	F
F	T

Two-variable truth tables:

p	q	p ∧ q
T	T	T
T	F	F
F	T	F
F	F	F

Not counting the title row, how many rows will there be in a truth table with n variables

Let’s make a chart:

Number of variables	Number of rows	As powers of 2
1	2	21
2	4	22
3	?	?
…	…	…
n	?	?

See if you can figure out values for the question marks. Then continue to the next page.