Exam ? (1 Viewer)

[googy_1985]

Hey, this is a question out of a BOS paper. They said the correct answer was C. I have no IDEA???? Could anyone explain this 2 me... Thanks

20. The following seven-bit ASCII character and parity bit were transmitted as:
ASCII character Parity
1011010 0

They were received as:
ASCII character Parity
1010010 1

(A) They were sent as odd parity and would be interpreted by the receiver as
correct.
(B) They were sent as odd parity and would be interpreted by the receiver as
incorrect.
(C) They were sent as even parity and would be interpreted by the receiver as
correct.
(D) They were sent as even parity and would be interpreted by the receiver as
incorrect.

 

[Morgues]

if its odd parity then in the first 7 ascii characters the 1s must add up to an odd number, if they dont then the 8th bit is set as a 1, if they do then the 8th bit is a 0

same with even parity except the 1s must add up to an even number

its sent as 1011010 0 so there are 4 1s, even and 8th bit is set to 0 therefore it is even parity

if its sent as even parity it must be received as even as well to be correct
its received as 1010010 1

3 1s in the first 7 bits however the 8th bit is set to 1 therefore it is even and the transmission has been correct