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

69. p1+c2+p3...+c100=?

70. Is it prime?

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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.**

**If it ain't broke, fix it until it is.**

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

71. p47 - p46

72. p38 / p27

Mathaholic | 17th most active poster | 681st most recent person to join MIFF | Person | rrr's classmate

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 97,227

Hi;

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

**If it ain't broke, fix it until it is.**

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
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73. p2^2

74. add the digits of #73

Mathaholic | 17th most active poster | 681st most recent person to join MIFF | Person | rrr's classmate

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 97,227

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

**If it ain't broke, fix it until it is.**

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
- Posts: 3,020

Correct!

# 75 squared

# 76 cubed

# 77 (sum of digits of #75) cubed

# 78 (sum of #76 and #77) raise to the fifth power

# 79 (sum of digits of #78) squared

# 80 Is (sum of digits of #75-79) prime?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 97,227

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

**If it ain't broke, fix it until it is.**

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
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# 81. to the four

# 82. prime?

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**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,646

Can you explain these a bit? I do not understand the questions.

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**mathaholic****Member**- From: Earth
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- Posts: 3,020

Okay. I'm sorry, but:

#81. What is 81^4?

#82. Is (Sum of digits of 81^4) prime?

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**ShivamS****Member**- Registered: 2011-02-07
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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
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I mean sum of digits, like 4+3+0+4+6+7+2+1. Anyways, nice try!

I'll write the items more user friendly.

83. What is 3 to the 5?

84. Multiply that answer by itself.

85. Multiply it by the nth prime (let n be the answer to #83).

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**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,646

I missed the sum part, sorry. The question you asked in the last post was clear enough, thanks.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 97,227

Hi;

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

**If it ain't broke, fix it until it is.**

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**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,646

Please hide your answers bobbym or you will receive an infraction.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 97,227

Sorry, latex error.

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

**If it ain't broke, fix it until it is.**

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
- Posts: 3,020

It's okay. Time to sharpen our minds!

#86. 1+2+4+8+1+6+3+2+6+4+1+2+8...+1+0+4+8+5+7+6

#87. 1+3+9+2+7+8+1+2+4+3+7+2+9...+3+8+7+4+2+0+4+8+9

#88. 1+5+2+5+1+2+5+6+2+5+3+1+2+5...+9+7+6+5+6+2+5

Note: Give me the pattern first before the sum. Both in separate posts.

#89. Sum of digits of #86-88.

After solving for the sum of 86, 87 and 88, respectively, answer this in a separate post, again.

*Last edited by mathaholic (2014-05-18 14:02:41)*

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 97,227

Hi;

I do not understand the questions please explain.

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

**If it ain't broke, fix it until it is.**

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**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,646

*Last edited by ShivamS (2014-05-28 01:27:46)*

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
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Hmm, since I'm too lazy to check...

#90. What is the square root of 121?

#91. It's obvious that it's prime. But, does the sum of its digits equal a prime number, too?

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**ShivamS****Member**- Registered: 2011-02-07
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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
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Whoops, I forgot to specify:

#91. Does the sum of the digits of the answer in #90 prime?

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**ShivamS****Member**- Registered: 2011-02-07
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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 97,227

Hi;

Should be #92

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

**If it ain't broke, fix it until it is.**

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