How to solve using substitution? i think the answer is 9, 5 but i need to show work.

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

Which undefined geometric term is described as a location on a coordinate plane that is designed by an ordered pair (x,y) ?

Determine the required value of the missing probability to make the distribution a discrete probability distribution. x p(x) 3 0.23 4 ? 5 0.51 6 0.08 p(4) = nothing  (type an integer or a decimal.)