# In a digital circuit which was to implement (A B) + (A)XOR(B), the designer implements (A B) (A)XOR(B)  What is the probability of error in it ?

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Answered by: muddu krishna

• May 15th, 2007

If we draw truth table as follows

 A B AB A XOR B (AB)+(A XOR B) (AB) (A XOR B) 0 0 0 0 0 0 0 1 0 1 1 0 1 0 0 1 1 0 1 1 1 0 1 0

so, we are getting 3 wrong answers out of 4

probability of error is 3/4=75%

Showing Answers 1 - 4 of 4 Answers

#### unknown

• Dec 3rd, 2005

the ans is half.

#### Akhilesh patel

• Dec 15th, 2006

if you seen both statement :

(AB)+A XOR B   -------1

& (AB)*A XOR B  -------2

apply Demorgan's law on 1 statement,

then statement 1 = complement of [ (AB)*A XOR B ]-----3

statement 3 always gives the complement of statement. so statement 1 always worng in comparision of statement 2.

if statement 2 = 1

then statement 1 = 0

so, Error =100%

and probility error = 1.(ans)

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#### parth

• Feb 7th, 2007

ans is : probability of error is halfyou can check out with truth table alsoA B (AB)* (AB)+ ERROR PROB0 0 0 0 0.000 1 0 1 0.251 0 0 1 0.251 1 0 0 0.00SO total prob. of error is 50%

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#### muddu krishna

• May 15th, 2007

If we draw truth table as follows

 A B AB A XOR B (AB)+(A XOR B) (AB) (A XOR B) 0 0 0 0 0 0 0 1 0 1 1 0 1 0 0 1 1 0 1 1 1 0 1 0

so, we are getting 3 wrong answers out of 4

probability of error is 3/4=75%

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