Afair die is rolled repeatedly. use precise notation of probabilities of events and random variables for the solutions to the questions below.

(a) write down a precise sum expression for the probability that the first five rolls give a 3 at most two times.

(b) calculate the probability that the first 3 does not appear before the fifth roll.

(c) calculate the probability that the first 3 appears before the twentieth roll but not before the fifth roll

i don't even know man. edge inuity be messing with us. i had to ask a question too.

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places