một tổ 10 người sẽ được chơi hai môn thể thao là cầu lông và bóng bàn.Có 5 bạn đăng ký chơi cầu lông, 4 bạn đăng ký chơi bóng bàn ,có 2 bạn đăng ký chơi cả 2 môn hỏi. xác suất chọn được một bạn đăng ký...

To solve this problem, we can use the principle of inclusion-exclusion. The total number of people who signed up for badminton or table tennis is the sum of those who signed up for badminton, those who signed up for table tennis, minus those who signed up for both sports. We denote: - A: the set of people who signed up for badminton - B: the set of people who signed up for table tennis - n(A): the number of elements in set A - n(B): the number of elements in set B - n(A ∩ B): the number of elements in both sets A and B The probability P that a person chosen at random has signed up for badminton or table tennis is given by: \[P = \frac{n(A) + n(B) - n(A \cap B)}{10}\] Given that: \[n(A) = 5\] \[n(B) = 4\] \[n(A \cap B) = 2\] Substitute these values into the formula: \[P = \frac{5 + 4 - 2}{10} = \frac{7}{10} = 0.7\] So, the probability of choosing a person who signed up for badminton or table tennis is 0.7.