Find the probability that one receives a chocolate & a toffee

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Discussion Overview

The discussion revolves around calculating the probability that a randomly selected child receives both a toffee and a chocolate from a group of 35 students. Participants explore different interpretations of the problem, focusing on the implications of selection order and the nature of probability in this context.

Discussion Character

  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • Some participants propose that the probability of a child receiving both candies could be calculated as $\frac{1}{35} + \frac{1}{35} = \frac{2}{35}$, while others question whether it should be $\frac{1}{35} * \frac{1}{35}$.
  • One participant suggests that if a specific child (e.g., Anna) receives the toffee, the probability that she also receives the chocolate is $\frac{1}{35}$, leading to a combined probability of $\frac{1}{1225}$ if calculated multiplicatively.
  • Another participant argues that the chance of any one student receiving both candies is simply $\frac{1}{35}$, emphasizing that it does not depend on which student is selected first.
  • There is a discussion about whether the events are mutually exclusive and how the rules of probability apply in this scenario.
  • One participant clarifies that if a specific student is considered before the selection of candies, the probability would be the square of $\frac{1}{35}$, but in this case, the selection occurs after the first candy is given.

Areas of Agreement / Disagreement

Participants express differing views on how to calculate the probability, with no consensus reached on the correct approach. Some support the idea that the probability is $\frac{1}{35}$, while others present alternative calculations and interpretations.

Contextual Notes

Participants highlight the importance of selection order and the implications of defining the problem, which may affect the interpretation of probabilities involved.

mathlearn
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Out of 35 students a toffee is given to a randomly selected child & a chocolate is also given to a randomly selected child . FInd the probability that the same same child get both

(Party) Hmm my answer would be $\frac{1}{35}+\frac{1}{35}=\frac{2}{35}$

or I doubt whether is it $\frac{1}{35}*\frac{1}{35}$
 
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mathlearn said:
Out of 35 students a toffee is given to a randomly selected child & a chocolate is also given to a randomly selected child . FInd the probability that the same same child get both

(Party) Hmm my answer would be $\frac{1}{35}+\frac{1}{35}=\frac{2}{35}$

or I doubt whether is it $\frac{1}{35}*\frac{1}{35}$

Hey mathlearn! ;)

Suppose the toffee is given to Anna, who is one of the 35 students, we don't care which one.
Now where does the chocolate land?
There are 2 possibilities: either it goes to Anna, or it goes to one of the other 34 students.
Care to consider what the chance is that Anna (who already has the toffee) gets the chocolate? (Wondering)
 
I like Serena said:
Hey mathlearn! ;)

Suppose the toffee is given to Anna, who is one of the 35 students, we don't care which one.
Now where does the chocolate land?
There are 2 possibilities: either it goes to Anna, or it goes to one of the other 34 students.
Care to consider what the chance is that Anna (who already has the toffee) gets the chocolate? (Wondering)

Probability that Anna gets the toffee $\frac{1}{35}$

Probability that Anna gets the chocolate $\frac{1}{35}$

Now depicting this information in a tree diagram.

View attachment 6080

Probability that she gets both $\frac{1}{35} * \frac{1}{35} = \frac{1}{1225} $

Correct?

Many Thanks (Smile)
 

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mathlearn said:
Probability that Anna gets the toffee $\frac{1}{35}$

Probability that Anna gets the chocolate $\frac{1}{35}$

Now depicting this information in a tree diagram.
Probability that she gets both $\frac{1}{35} * \frac{1}{35} = \frac{1}{1225} $

Correct?

Many Thanks (Smile)

Not quite. (Shake)
It doesn't matter which student is Anna.
There is just the 1 chance in 35 that whoever got the toffee will get the chocolate.
So the chance that one student gets both the toffee and the chocolate is $\frac 1{35}$. (Thinking)
 
mathlearn said:
Out of 35 students a toffee is given to a randomly selected child & a chocolate is also given to a randomly selected child . FInd the probability that the same same child get both

(Party) Hmm my answer would be $\frac{1}{35}+\frac{1}{35}=\frac{2}{35}$

or I doubt whether is it $\frac{1}{35}*\frac{1}{35}$
Do you really think that the probability of being given a toffee and a chocolate could be greater than the probability of being given the toffee only?
 
I like Serena said:
Not quite. (Shake)
It doesn't matter which student is Anna.
There is just the 1 chance in 35 that whoever got the toffee will get the chocolate.
So the chance that one student gets both the toffee and the chocolate is $\frac 1{35}$. (Thinking)

This event ain't mutually exclusive , I guess (Thinking)

The probability that one gets a toffee and chocolate = $\frac 1{35}$

So got to agree but I wonder whether the rule of If or And of probability is used here

HallsofIvy said:
Do you really think that the probability of being given a toffee and a chocolate could be greater than the probability of being given the toffee only?

Thank you very much for the advice , Yes so now I see that the probability of getting the chocolate and the toffee is equal to the probability of getting the toffee :)
 
Suppose you number the 35 students, that is, assign each one a unique number from 1-35. If you are asked what is the probability that student #12 will get both candies, then you would find that probability is the square of 1/35. You have selected a student before the first candy is given out and so the 1/35 is applied twice.

In this problem though, a student isn't selected until the first candy is given, and only then are we to consider what is the probability that that student will then receive the second candy, which is just 1/35. :D
 
MarkFL said:
Suppose you number the 35 students, that is, assign each one a unique number from 1-35. If you are asked what is the probability that student #12 will get both candies, then you would find that probability is the square of 1/35. You have selected a student before the first candy is given out and so the 1/35 is applied twice.

In this problem though, a student isn't selected until the first candy is given, and only then are we to consider what is the probability that that student will then receive the second candy, which is just 1/35. :D

Thank you very much MarkFL (Happy) (Party)

So this case changes from the others as the child is not exactly told in the beginning but instead we choose he/she after the toffee is given

Many Thanks :D
 

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