Year 10 Test Review: Probability

[rutoyou]

why is this so easy??? i could get all the questions correct. must be an american test.

[georgewolfe]

I'm not sure the reasoning for question 5 is valid. I don't think the proposed definition of Kevin beats Jim as "P(white) - P(green)" is correct.

The question is slightly ambiguous as it does not specify whether landing on either colour results in a re-spin, so I'll cover both cases below. (I would probably assume that landing on another colour results in a respin, but regardless, it's probably a good idea to specify: "The players keep spinning until a player wins" or something similar for further clarity.)

If we assume that the spinner landing on another colour results in a re-spin, then the P(Kevin beats Jim) = P(White appears before green). In this case, we can simply ignore the respins/other colours, as they do not affect the eventual outcome. This leaves P(Kevin beats Jim) as (Proportion which is white) / (Proportion which is white or green), leaving options A and C as being equally correct. (Both a 2/3 chance of Kevin winning). Their relative sizes don't actually matter, they simply determine how long the game will take to conclude.            

If we assume that the spinner landing on another colour results in a draw/game finish where neither player wins, then P(Kevin beats Jim) = P(Kevin wins after one spin) = P(White), leaving options A and B as being equally correct, at 50%     

A is the safest answer, as it satisfies both requirements, but in neither case is it strictly correct.

[deepaknicedramapleasesenda]

Tum mere youtu pe vidio send kyu k r h