Please help me for this problem.

If p(a) = 0.70 and p(b) = 0.20, then a and b are independent events if

Which of the following are independent events? a) knowing that it is going to rain tomorrow, and bringing an umbrella to schoolb) knowing that you have to get up early tomorrow, and going to bed before 9 p. mc) knowing that it is going to rain tomorrow, and going to bed before 9 p. md) knowing that you have a test in school tomorrow, and studying thw night before

The data set represents the ages of players in a chess club. 27, 34, 38, 16, 22, 45, 54, 60. what is the mean absolute deviation of the data set?