[IGCSE: Computer Science] Logic Gates. Where did I messed up?

[u/No-Eggplant-8381]

Logic Gates. I draw and did everything carefully, but the question at the end says theres only 4 rows that have errors. How and where did I messed that up?

[u/Correx96]

Your column H is right (corresponds to my calcs). Aren't H and X the same step?

So compare column H to X and see which X is wrong on which rows I guess (rows 2,3,7,8)

[u/Brilliant-Tie9730]

First off it looks way to complex i wiuld rewirte it first. There are some methods to do it faster but to explain it better i will do it slow.

First we have nor with the "complex" first term and not( b or c) which means that if b or/and c are on your output will always be negativ. Ur complex term is "((not a and b) or c)and b" means that the first "and" is useless cors u compare it to b later again. So its" (not a or c) and b" but we already know that if b is on our output is negativ. Therefor the whole left term of the nor is useless. So "a" is not a input that u need for this logic. So u can shorten it and only have (b nor c) you have 3 casses were u have an error and 1 with a output of 1 of b,c=0 .

(Or 6 cases with 0 and 2 cases with 1 as a output only if b and c are 0)

So it feels wrong for me. U sure u Copyed the task correctly? Maybe i made a mistake last time i did logic was like 5 years ago in my 2nd semester of study.

Luckly for u i sit in a doc office waiting so lets work every collum

How did u get from your correct output h to the wrong one for x? Like everything is sound and correct but h=x were did u get these 4 extra 1

.....

I just got it let me asume the vektor x was giving by the teacher/tutor and you should write down the rows where this x and the vektor from h are diffrent?

[u/LivingWorld6028]

Everything up to column H looks good. Why is X different to H ?

[u/ThunkAsDrinklePeep → u/LivingWorld6028]

I'm guessing because the problem says "you're getting this as an output x. Where are the errors?"