How is the truth table of 3 input Logic Gates derived?

Devika B S

Joined Mar 8, 2017
144
I am not able to understand the logic behind the truth tables of 3 input gates. For example, consider the input: 1 0 0
Output of this is 1 as per the truth table.
But isn't it 1.(0.0) = 1.0 = 0 ? Am I not allowed to use Boolean algebra in this manner?

( I have this intuition that there is a terrible blunder being committed somewhere, but I am not very sure of the concepts involved in truth tables)

MrChips

Joined Oct 2, 2009
24,982
Can you post an link or reference to the truth table in question?
There is either an error or a misunderstanding.

Devika B S

Joined Mar 8, 2017
144
Can you post an link or reference to the truth table in question?
There is either an error or a misunderstanding. MrChips

Joined Oct 2, 2009
24,982
That is a mistake.

Only the last line A=1, B=1, C=1 gives Output =1 for A.B.C.

• Devika B S

Devika B S

Joined Mar 8, 2017
144
Can you post an link or reference to the truth table in question?
There is either an error or a misunderstanding. But another truth table for AND gate online is this. So I guess the first truth table is not that of AND gate? I am not having 3 input gates in my textbook. I am looking at materials online.

Devika B S

Joined Mar 8, 2017
144
That is a mistake.

Only the last line A=1, B=1, C=1 gives Output =1 for A.B.C.
OK Thank you for the clarification.

Papabravo

Joined Feb 24, 2006
17,535
Other properties of the AND (&) function is that it is commutative and associative.
1. A&B = B&A -- Commutative Property
2. (A&B)&C = A&(B&C) -- Associative Property
The gates work the same way as the algebra.

• Devika B S