# math

posted by on .

You randomly draw letter tiles from a bag containing the letters from the word INDEPENDENT.

1. You randomly draw an N. Then, without replacing the first letter, you pick a D. Tell whether the events are independent or dependent. Then find the probability that both events occur.
---> I think it's a dependent event. But I'm having trouble solving for the probability.

2. You randomly pick a T. You replace it. Then you pick an E. Find the probability that both events occur.

I know this is the second time I'm posting this question, and I'm really sorry, but it's kind of urgent :(

Thanks again!

• math - ,

1. Draws without replacement are generally dependent. The outcome of the second draw is dependent on that of the first.
Give a try for the calculation of probability, and post what you have.

2. Draws with replacement are generally independent. So calculate the probability of each event and combine them ... how?

• math - ,

1.
In the first draw, there are 3 N's out of 11 letters. So you should be able to figure out the probability P1 (if necessary, see your previous post).
For the second draw, there are 2 D's in the 10 letters left (without replacement).
The probability is therefore P2.
The probability that BOTH of them will occur is P1.P2.
Can you work that out and post me the result?

• math - ,

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