A and B write a test A says " i got a third of the ques. wrong" B says " i got 5 wrong" together they got three quarters of the questions correct. how many did a get correct.
RE: A and B write a testA says " i got a third o...
Hey where did you get 3/4 * 2x from. what rule did you apply. I too have solution:(here 'v' > union & '^' > intersection)|A| x/3|B| 5|A v B| 3x/4so | A' | 2x/3| B' | x - 5we know that |A v B| |A| + |B| - |A ^ B|applying this we get | A ^ B | 5x/12 - 5and| A' | + | B' | | A' v B' | + | A' ^ B' |also applying de Morgan's law (see: http://mathworld.wolfram.com/deMorgansLaws.html)| A' | + | B' | | (A ^ B)' | + | (A v B)' |that is2x/3 + (x-5) [ x - (5x/12 -5)] + (x - 3x/4) > 5x/3 -5 7x/12 + 5 + x/4 > 10x/12 10 > x 12there for A got 2x/3 correct which is 8 questions correct.
RE: A and B write a testA says " i got a third o...
Let the total number of questions be 'x'. Then for A the total correct ans is n(A) n-n(A)'i.e. x-(1/3).Similarly for B the total correct ans is x-5.Now total correct ans by A & B is 3/4.So by de morgans law n(AUB) n(A)+n(B)-n(A^B).i.e.x (x-1/3)+(x-5)-(3/4). So x (2x-73/12). So x 73/12. So substituting the value in 1 equation A got 205/36 ans correct.
RE: A and B write a testA says " i got a third of the ques. wrong"B says " i got 5 wrong"together they got three quarters of the questions correct.how many did a get correct.
A got 1/3 of the questions wrong it means 33
So A got 67 correctly
When A got 67 correct and Total A and B is 75
Then B's Correct is 83
Therefore B's Wrong is 17
and The total No. of questions where 5/.17 30
I am sure the qustions are same for A and B
Therfore 1/3 of 30 is 10 and A got 20 questions correct
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