Yup, glad to hear that you also think the OA to the first one should be '10%' Stuart.
Mutual_help,
the formula you used is wrong,
when you say,
n(A int B) + n(A int C) + n(B int C), elements of (A int B int C) are included 3 times in this....
hence, you have to subtract - 2 X n(A int B int C) from the answer you are getting to get the right answer.
hence, it will be, 20 - 2(5) = 10%.
Mutual_help,
the formula you used is wrong,
when you say,
n(A int B) + n(A int C) + n(B int C), elements of (A int B int C) are included 3 times in this....
hence, you have to subtract - 2 X n(A int B int C) from the answer you are getting to get the right answer.
hence, it will be, 20 - 2(5) = 10%.
