Please explain how to get the answer​

Use the side-by-side boxplots shown to complete parts (a) through (e). 0 30 60 90 120 y x

In the final round of trivia competition, contestants were asked to name as many states that begin with the letter m as they could in 15 seconds. the bar graph shows the number of states the contestants were able to name. how many contestants participated in the final round of the competition? a) 6 b) 8 c) 14 d) 20

What number should be added to both sides of the equation to complete this square? x^2-10x=7