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- #1

#### karush

##### Well-known member

- Jan 31, 2012

- 2,771

the numbers in () and boxes are mine, easy problem but still can make mistakes..

- Thread starter karush
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- Thread starter
- #1

- Jan 31, 2012

- 2,771

the numbers in () and boxes are mine, easy problem but still can make mistakes..

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- #2

- Mar 5, 2012

- 8,856

Hey karush!

the numbers in () and boxes are mine, easy problem but still can make mistakes..

Your table looks just fine and so is your answer to the first question.

However, for the second question, you have to consider what the total number of possibilities is. Apparently you thought it was a 100, but then you did not take into account that it is given that it is a boy. You should look

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- #3

- Jan 31, 2012

- 2,771

see what you mean, so it should be $\displaystyle\frac{13}{38}$Hey karush!

Your table looks just fine and so is your answer to the first question.

However, for the second question, you have to consider what the total number of possibilities is. Apparently you thought it was a 100, but then you did not take into account that it is given that it is a boy. You should lookonlyat the boys.

- Admin
- #4

- Mar 5, 2012

- 8,856

Nope. Not yet.see what you mean, so it should be $\displaystyle\frac{13}{38}$

It should be the number of boys that watch television divided by the total number of boys.

You just calculated the probability that a student is a boy, given that (s)he prefers to watch television.

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- #5

- Jan 31, 2012

- 2,771

$\displaystyle\frac{13}{46}$