Question: If the universal set U has 100 elements, set A has 40 elements, and set B has 30 elements with 10 elements in both A and B, how many elements are in neither A nor B?
Options:
Correct Answer: 60
Solution:
Using the principle of inclusion-exclusion, the number of elements in either A or B is: (A + B - Both) = 40 + 30 - 10 = 60. Therefore, elements in neither = U - (A βͺ B) = 100 - 60 = 40.