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Bunuel
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Inacc P Inacc P Acc P Acc P
Inacc E Acc E Inac E Acc E
_______ _______ ______ _____

a b c d


a/a+b = .6.

a/a+c = .75

a=.03

Find d


.03=.18+.6b. b=.02

.03=(.09/4)+.75c. c=.01

a+b+c+d=1

d=1-.03_.02-.01 = .94

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incorrect papercorrect paper
incorrect electronic0.6x=0.75y=3%0.25yy% let
correct electronic0.4xz=? let
x% let100%
as per given conditions above grid can be formed
so 0.6x=3% so x=5% and 0.75y=3% so y=4%
if x=5% so the box below z=? will read as 95%
and if y=4% so 0.25y=1%
hence required probability=z=95-1=94% both entries correct
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IMO B
I tried to solve it like this:
Let Ei be the event of electronic inaccurate & Pi be the event of Paper inaccurate.
P(Ei/Pi) = 0.6 = P(Ei intersection Pi) / P(Pi) = 0.03/P(Pi), solving P(Pi) = 0.04
similarly P(Pi/Ei) = 0.75 = P( Ei intersection Pi)/P(Ei) , solving P(Ei) = 0.05
So , P(Pi U Ei) = 0.04+0.05-0.03 = 0.06
Let Pa = paper acurate, Ea= Electronic acurate
Therefore: P(Pa inetrsection Ea) = 1-0.06 = 0.94

Please let me know if my logic is correct?
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