# truth table for circuit

#### nothereyet

Joined Jan 18, 2023
4
Fill in the truth table the following circuit. Ignore rows not included in the table.
Can I please get assistants with this question have for an assignment. I have no clue what to do

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#### dl324

Joined Mar 30, 2015
16,143
Welcome to AAC!
Can I please get assistants with this question have for an assignment. I have no clue what to do
The way Homework Help works is you show us your best efforts and we try to guide you past the place where you're getting hung up.

I guess you have to ignore the fact that whoever wrote the problem didn't know what they were doing when they grounded the carry output from the half adder on the right.

#### nothereyet

Joined Jan 18, 2023
4
Welcome to AAC!
The way Homework Help works is you show us your best efforts and we try to guide you past the place where you're getting hung up.

I guess you have to ignore the fact that whoever wrote the problem didn't know what they were doing when they grounded the carry output from the half adder on the right.
This is exactly how we got the question. I have tried to google examples and explanations but I can't get my head around this problem hence nou effort shown in the post

#### dl324

Joined Mar 30, 2015
16,143
I have tried to google examples and explanations but I can't get my head around this problem hence nou effort shown in the post
If you were given this question, you must have been taught how to solve it without needing to search the internet for answers. We won't give you answers because you won't learn anything.

Do you know how a half adder works?

This is exactly how we got the question.
We can't do anything about instructors who don't know what they're doing.

#### MrChips

Joined Oct 2, 2009
29,848
If you have a half adder with two inputs A and B, write out the resulting outputs with all possible combinations of A and B.

#### nothereyet

Joined Jan 18, 2023
4
If you were given this question, you must have been taught how to solve it without needing to search the internet for answers. We won't give you answers because you won't learn anything.

Do you know how a half adder works?

We can't do anything about instructors who don't know what they're doing.
I am studying online and we received a pdf with info and it's difficult to understand when there is only 5 pages of explanations on boolean algebra. worst case scenario is that I don't get marks for that question. I still have a week before submission so I will try to spend some time understanding the question, and this is the only one I am left struggling as most of the question is about truth tables and the application of arithmetic operators.

#### WBahn

Joined Mar 31, 2012
29,506
This is exactly how we got the question. I have tried to google examples and explanations but I can't get my head around this problem hence nou effort shown in the post
Start with just the left half adder with the two inputs 'a' and 'b'. What is the carry and sum output for that block for all four possible combinations of 'a' and 'b'.

#### dl324

Joined Mar 30, 2015
16,143
I am studying online and we received a pdf with info
You get what you pay for.
it's difficult to understand when there is only 5 pages of explanations on boolean algebra
You're not being asked to do any boolean algebra in this problem.
I am left struggling as most of the question is about truth tables and the application of arithmetic operators
I'll ask again. Do you know how a half adder works? Progress will be slow and tedious if you refuse to cooperate.

#### nothereyet

Joined Jan 18, 2023
4
You get what you pay for.
You're not being asked to do any boolean algebra in this problem.
I'll ask again. Do you know how a half adder works? Progress will be slow and tedious if you refuse to cooperate.
Sorry if I am replying slow. Its 2am in he morning and I am still watching videos on this subject.
so what i understand is that a half adder is used for addition of binary numbers. it has 2 inputs and then 2 outputs - sum and carry

#### dl324

Joined Mar 30, 2015
16,143
what i understand is that a half adder is used for addition of binary numbers. it has 2 inputs and then 2 outputs - sum and carry
Can you draw the truth table for a half adder?

#### WBahn

Joined Mar 31, 2012
29,506
Sorry if I am replying slow. Its 2am in he morning and I am still watching videos on this subject.
so what i understand is that a half adder is used for addition of binary numbers. it has 2 inputs and then 2 outputs - sum and carry
Don't worry about how fast you reply -- you reply when you are able to. The same as us.

If all you know about a half-adder is that it has two inputs and two outputs and what the names of the outputs are, then there is your problem. How can you possibly answer a question about what the outputs are for given input conditions if it uses a part and all you know about it is the names of the output pins?

So go read up and learn what a half adder is and what the outputs are for all of the various possible input conditions. Then make sure that you understand how this makes sense in terms of it being a part that performs 1-bit by 1-but binary addition.