Probability question (1 Viewer)

[SonOfAGun]

A box contains 6 white balls and 2 black balls. Balls are selected at random, one at a time, and not replaced. A note is kept of the number, X, of the draw which first yields a black ball. If this experiment is repeated several times find:

(i) the most probable value of X
(ii) the probability that X > 4

im still a bit scratchy on probability bcuz we just started at skool so can sumone confirm if my answers are right:
(i) X = 2
(ii) 0.0542

 

[SonOfAGun]

anyone?

this was actually a question 5 in a 4U trial

 

[xV1P3R]

For the first one, I think you just calculate probabilities of all X's and compare them to find the biggest ie. X = 1.
P(X=1) = 0.25
P(X=2) = 3/14
P(X=3) = 5/28
P(X=4) = 1/7
P(X=5) = 3/28
P(X=6) = 1/14
P(X=7) = 1/28

For part 2, just add up X = 5,6,7 to get your answer.

[Edit: I'll double check on the first answer. Doesn't seem right]
Yep, Question 1 is looking for mode which should be 1.

 

[SonOfAGun]

tnx m8.