The probability for event A is 0.4, the probability for event B is 0.2, and the probability of events A and B is 0.1. Why are the events not independent?

The sum of P(A) and P(B) is greater than P(A and B).
The product of P(A) and P(B) is greater than P(A and B).
The product of P(A) and P(B) is not equal to P(A and B).
The sum of P(A) and P(B) is not equal to P(A and B).

Two groups of students were asked how many hours they spent reading each day. the table below shows the numbers for each group: group a 1 2 1 1 3 3 2 2 3 group b 3 2 3 2 2 2 1 1 2 based on the table, which of the following is true? the interquartile range for group a students is 0.5 less than the interquartile range for group b students. the interquartile range for group a students is equal to the interquartile range for group b students. the interquartile range for group a employees is 0.5 more than to the interquartile range for group b students. the interquartile range for group a employees is 1 more than the interquartile range for group b students.