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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
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1. What is the 5th prime number, which is also an additive prime?

2. What is a Mersenne prime?

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"What is the square root of 2? 1.4141592653589793238" Seriously, I thought it was that. Too round?

3.141592653589793238...

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
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**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
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Easy, right? No scoreboard this time.

3. Complete the sequence: 3, 7, 13, 19, 29, __ , __

4. What is the perfect number that when you subtract 1 to it, you get a prime?

"What is the square root of 2? 1.4141592653589793238" Seriously, I thought it was that. Too round?

3.141592653589793238...

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,528

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
- Posts: 2,870
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Yes.

5. What is the prime exponent of 5 wherein when added the digits of the number, you get a prime number (5^n = digit 1 + digit 2... = p)?

6. Which is the first twin triplet (3 consecutive twin primes)?

"What is the square root of 2? 1.4141592653589793238" Seriously, I thought it was that. Too round?

3.141592653589793238...

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,528

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
- Posts: 2,870
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That was a tricky one!

7. Complete the digits:

8. Is 36+(9*12)-(11*(2+3) prime?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,528

I do not understand 7.

8 is missing a parentheses.

**In mathematics, you don't understand things. You just get used to them.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
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Hint: On 7, it is the largest known prime.

For 8, whoops, sorry.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,528

**In mathematics, you don't understand things. You just get used to them.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
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7. Yes.

8. The answer was 89. Good.

9. When counted the letters of mathaholic, is it prime or composite?

10. What is the first prime number from 201 - 300?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
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For 9) the number of letters you want counted?

**In mathematics, you don't understand things. You just get used to them.**

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**mathaholic****Member**- From: Juliania
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Number of letters of my username, mathaholic.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,528

]

**In mathematics, you don't understand things. You just get used to them.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
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11. Is this true? c + c = p

12. What is the 1,000,000th prime number?

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**bobbym****Administrator**- From: Bumpkinland
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11) I do not understand the question.

**In mathematics, you don't understand things. You just get used to them.**

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**mathaholic****Member**- From: Juliania
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11. Composite number + Composite number = prime number

12. Good. Just 11

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,528

**In mathematics, you don't understand things. You just get used to them.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
- Posts: 2,870
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Sometimes it is false, too: 4 + 6 = 10, or 4 + 4 = 8

13. You might not be able to answer this: What is 13^13 - (13*(13th prime number)) ?

14. Let's ease it off a little. If 2 + 3 = 5, what is 3 + 5 ? **Note: This is not literal addition.**

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,528

**In mathematics, you don't understand things. You just get used to them.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
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13. Okay.

14. I actually made a puzzle of 1 + 4 = 9 = 4 + 9 = ?.

Now, look:

2 is the first prime number, and 3 is the second prime number. Add the orders, 1 + 2 = 3rd prime number = 5.

3 is the second prime number, and 5 is the third prime number. 2 + 3 = 5th prime number = 2, 3, 5, 7, **11**.

15. What is the 17th prime number?

16. Square the 17th prime number, and what is it?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,528

**In mathematics, you don't understand things. You just get used to them.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
- Posts: 2,870
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There are 2 answers for 16:

17[sup]2[/sup] = 289

The 289th prime number is 1,879

Another solution is what you did: 17p[sup]2[/sup]

17. What is the 5th prime number + the 5th prime number squared?

18. What is the 8th prime number + the 1st prime number cubed?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,528

**In mathematics, you don't understand things. You just get used to them.**

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
- Posts: 2,870
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17. Good

18. Good

Bonus!

19 - 20. If 97 is the 25th prime number, is 199 the 50th prime number? If no, what is it?

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