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A die is thrown twice. What is the probability that the sum of the number of dots is 4...

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saifealone | Student, Undergraduate | eNotes Newbie

Posted July 8, 2011 at 12:51 AM via web

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A die is thrown twice. What is the probability that the sum of the number of dots is 4 or 10?

 

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3 Answers | Add Yours

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giorgiana1976 | College Teacher | Valedictorian

Posted July 8, 2011 at 1:14 AM (Answer #1)

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Since the total number of faces of a die is 6, the probability to get one of the six faces of the die when it is thrown is:

P = 1/6

We know that this die is thrown twice, therefore the probability becomes:

P = 1/6*6 = 1/36

Now, let's analyze what combination of faces leads to the sum of number of dots of 4 or 10.

The value of the sum of dots is 4 when we have the following combinations:

1 + 3 = 4

2 + 2 = 4

3 + 1 = 4

Keeping in mind that the total number of dots a face can have is 6, the value of the sum of dots is 10 when we have the following combinations:

4 + 6 = 10

5 + 5 = 10

6 + 4 = 10

Therefore, we've identified 6 posssible outcomes, therefore the probability is:

P = 6/36

P = 1/6

Therefore, the probability that the sum of the number of dots is 4 or 10 is P = 1/6.

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samhouston | Middle School Teacher | (Level 1) Associate Educator

Posted July 8, 2011 at 7:09 PM (Answer #2)

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When a die is thrown twice, there are 36 possible outcomes.

3 of these outcomes give a sum of 4:

  • 1 and 3
  • 2 and 2
  • 3 and 1

 

3 of these outcomes give a sum of 10:

  • 4 and 6
  • 5 and 5
  • 6 and 4

Therefore, there are 6 outcomes that produce a sum of 4 or 10.

The probability is 6/36 = 1/6

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rnk | Student , Grade 10 | Honors

Posted July 9, 2011 at 1:40 AM (Answer #3)

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We will create the following table to sort out the problem

FIRST DICE -------->

1|   2|   3|   4|   5|   6

--------------------------------------------

1 |              2|  3|   4|   5|   6|    7

2 |              3|  4|   5|   6|   7|    8

3 |              4|  5|   6|   7|   8|    9

4 |              5|  6|   7|   8|   9|   10

5 |              6|  7|   8|   9| 10|   11

6 |              7|  8|   9| 10| 11|   12

 

 

From this table we can get the sum of the two dots in both cases.

thus, all possible outcome =  36

favourable outcome =  3 + 3 =6

probability = 6/36 = 1/6(Ans.)

 

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