PLEASE ANSWER QUICK!Kierran is trying to find the circumference of a circle. He knows that the radius (r) of the circle is 6 feet and that the diameter, d=2r. Which formula should he use? A) A=3.14(2r)^2
B) C=3.14(2r)
C) A=3.14d^3
D) C=3.14(2D)

On any given day, the number of users, u, that access a certain website can be represented by the inequality 1125-4530 which of the following represents the range of users that access the website each day? u> 95 or u < 155 95> u> 155 u< 95 or > 155 95

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great