Please help my small brain don’t know this stuff

Examine the following sets of events. set a: {1, 5, 7, 9, 14} set b: {2, 5, 6, 8, 14, 17} which of the following represents the intersection of set a and set b ? {∅} {5, 14} {1, 2, 5, 6, 7, 8, 9, 14, 17} {1, 2, 6, 7, 8, 9, 17}

Suppose a ball is dropped fromca height of 6ft. it bounces back up but time it bounces, it reaches only 7/10 of its pervious height. what is the total of each height that the ball reaches after 5 bounces

At the olympic games, many events have several rounds of competition. one of these events is the men's 100-meter backstroke. the upper dot plot shows the times (in seconds) of the top 8 finishers in the final round of the 2012 olympics. the lower dot plot shows the times of the same 8 swimmers, but in the semifinal round. which pieces of information can be gathered from these dot plots? (remember that lower swim times are faster.) choose all answers that apply: a: the swimmers had faster times on average in the final round. b: the times in the final round vary noticeably more than the times in the semifinal round. c: none of the above.