A bag contains two red beads and two green beads

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Discussion Overview

The discussion revolves around calculating the probability that not all beads in a bag are red after three replacements, where the bag initially contains two red beads and two green beads. Participants explore different approaches to solving this probability problem, including mathematical reasoning and visual representation.

Discussion Character

  • Mathematical reasoning, Exploratory, Homework-related

Main Points Raised

  • One participant seeks help with the probability question regarding the beads and their replacements.
  • Another participant estimates the probability to be 71.875%, though this is presented as a guess.
  • A different participant suggests that the probability can be calculated by considering the outcomes of pulling out the two green beads in the first three replacements, providing a specific mathematical expression for this calculation.
  • Another participant proposes using a tree diagram to visualize all possible outcomes of the replacements.

Areas of Agreement / Disagreement

There is no consensus on the correct probability value, and multiple approaches to the problem are presented without resolution.

Contextual Notes

Participants' calculations and assumptions about the replacement process and probabilities are not fully detailed, leaving some steps and dependencies unclear.

Derivative86
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A bag contains two red beads and two green beads. You reach into the bag pull out a bead, replacing it with a red bead regardless of the color you pulled out. What is the probability that all beads in the bag are not red after three such replacements?
 
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What is the probability that all beads in the bag are not red after three such replacements?

Hmmm, at a guess I'd say 71.875% :)
 
I would think it is the probability of pulling out the two green beads in the first three replacement. So if my math is correct, it should be:

(2/4 * 1/4 * 4/4) + (2/4 * 3/4 * 1/4) + (2/4 * 2/4 * 1/4)
 
You could draw a tree of all the possibilities.
 

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