How many times will the point at C and D in one play

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Discussion Overview

The discussion revolves around calculating the probability of two arrows landing in specific areas (C and D) on a spinner game played multiple times. Participants explore different approaches to determining the expected outcomes based on the game's setup and the areas designated for the arrows.

Discussion Character

  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant suggests that if it takes 3 tries to land in E and another 3 tries to land in D, then the expected number of times the arrows would land in C and D over 120 plays is about 13 times, calculated as 120 divided by 9.
  • Another participant proposes that if the arrows are spun randomly, the probability of the first arrow landing in C is 1/2, and similarly for the second arrow landing in D, leading to a combined probability of 1/4 for both arrows landing in C and D. This would suggest an expected outcome of about 30 times in 120 spins.
  • A different participant points out that if all areas in each spinner had the same area, the probability of landing in C and D would be 1/3 for each, resulting in a combined probability of 1/9. However, they note that the diagram indicates C and D each occupy 1/2 of the total area, not 1/3.
  • Another participant expresses uncertainty about the probability concepts involved and seeks clarification on whether this scenario involves combinations.

Areas of Agreement / Disagreement

Participants present differing calculations and interpretations of the probabilities involved, with no consensus reached on the correct approach or final answer.

Contextual Notes

Participants reference a diagram that is not visible in the discussion, which may influence their understanding of the areas involved in the probability calculations. There is also uncertainty regarding the definitions and applications of probability concepts among some participants.

karush
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https://www.physicsforums.com/attachments/139
a game is played by rotating 2 arrows from the center of two circles per play with the pointer landing in one of the designated area's A B and C in one and E F and D in the other.
If played 120 times about how many times would the arrows land on the area of C and D in one play
wasn't sure of probablilty forumula to use for this but since it takes 3 tries to land in E and another 3 tries to Land in D
So 3x3=9 and 120/9 = 13.3 or about 13 times
so if this is correct. basically how is this set up with a probability is this a combination?
Thanks ahead(Cool)
 
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karush said:
https://www.physicsforums.com/attachments/139
a game is played by rotating 2 arrows from the center of two circles per play with the pointer landing in one of the designated area's A B and C in one and E F and D in the other.
If played 120 times about how many times would the arrows land on the area of C and D in one play
wasn't sure of probablilty forumula to use for this but since it takes 3 tries to land in E and another 3 tries to Land in D
So 3x3=9 and 120/9 = 13.3 or about 13 times
so if this is correct. basically how is this set up with a probability is this a combination?
Thanks ahead(Cool)
Assuming the arrows are spun so they land in a random area, the probability that on any spin the first arrow lands in C is 1/2 (as it accounts for 1/2 of all the directions the arrow could end up in)

The same for the second arrow and D.

As the results of the spins of the two arrows are independent the probability that arrow 1 ends in C and arrow 2 ends in D is the product of the individual probabilities and so is (1/2)(1/2)=1/4

So in 120 spins you would expect about 1/4 of then to have the arrows in C and D which is about 30 times.

CB
 
karush said:
https://www.physicsforums.com/attachments/139
a game is played by rotating 2 arrows from the center of two circles per play with the pointer landing in one of the designated area's A B and C in one and E F and D in the other.
If played 120 times about how many times would the arrows land on the area of C and D in one play
wasn't sure of probablilty forumula to use for this but since it takes 3 tries to land in E and another 3 tries to Land in D
So 3x3=9 and 120/9 = 13.3 or about 13 times
so if this is correct. basically how is this set up with a probability is this a combination?
Thanks ahead(Cool)
IF all three areas in each spinner had the same area, THEN the probability of landing in C and D would be 1/3 so the probability of both landing in those areas would be 1/9 and your answer would be correct.
However, your picture shows that C and D each takes up 1/2 of the total area of the spinner, not 1/3.
 
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I see what you mean by possible 3rds however the problem gave this diagram and just asked probability of landing in C and D this is a realitively easy problem but I was wondering if this is probablitly combination (I don't know probability stuff hardly at all so trying to learn it)
looks like MHB is a good place to spend time... appreciatate much
 

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