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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

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

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

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

Good!

Example:

T[sub]4[/sub] means that you need to get the 5th triangular number because T[sub]0[/sub] is 1, the first triangular number.

Okay!

Next question:

Numbers 3 4 5

Operations T +

Answer 46

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

Hi;

The first triangular number is 0, so T0 = 0.

But using your definition we can say

T3 + T4 + T5 = 46

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

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

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

Oh. My classmate taught me that T thing.

Number 14 28 42

Operation + - [sup]2[/sup]

Answer 1764

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: 98,268

42^2 = 1764

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

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

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

New edition :

P * C.P = 5

P = Prime

C = Composite

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

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it can't be.

5 = 5*1 and there isn't any other factorisation

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'But our love is like the wind. I can't see it but I can feel it.' -A Walk to remember

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

Hi julianthemath;

5 only has the factorization of 5 x 1. 1 is not composite or prime. Please post another problem this one has no solution.

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

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

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

C.P means decimal number. Try again.

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**mathdad****Member**- Registered: 2013-04-13
- Posts: 21

julianthemath wrote:

New edition :

P * C.P = 5

P = Prime

C = Composite

Still not possible.

All P are such that P > 1. The smallest P is 2. And, the smallest C such that C > 0 is 4

Thus P * C.P >= 2 * 4.d = 8.0 + 2d (where 2d is 2 times the decimal part)

If you were trying to go for 2 * 2.5, then the 2 in 2.5 is not Composite, it is Prime.

*Last edited by mathdad (2013-04-22 09:04:17)*

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

Oh, well.

No answers, no points.

Wanna ask, mathdad? bobbym? Or just keep me?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

Hi;

Okay, let me see the answer. Please hide the answer cause someone else may still want to work on it.

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

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

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

81 + X - 4 = 85

Solve for X.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

Hi;

Thanks for the answer.

X = 0

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

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

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

Again!

81 + X - 4 = 85

You might have an error.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

H;

81 + X - 4 = 85

Add 4 to both sides:

81 + X = 89

Subtract 81 from both sides.

X = 8

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

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

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

Wow.

1777 - 777 + 777 * 777 = ?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

604729 is the answer.

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

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

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

Wow!

This time, there are points.

X + X = X

What makes this impossible to answer? 30 points

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

Nothing, X can be 0.

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

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

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

Oh. How do you like my signature? Funny, right?

Bobbym - 30

3 6 9 15 ? What is the fifth number?

*Last edited by julianthemath (2013-04-25 21:01:50)*

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

I like 21 as the nest number.

I worked a long time on bobbym - 30 but could not come up with anything.

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

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

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

Oh.

Bobbym - 60

If China has a population of 1,234,567,890,

India 123,456,789

USA 12,345,678

Indonesia 1,234,567

What is the population of Brazil?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 98,268

Is it 123 456 ?

How are the chickenpox?

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

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

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

No. I didn't have it, my cousins do. The start of the infection was during the afternoon I came home after my last exams. And now, some of my cousins are having the chickenpox. So, I just need to stay inside.

Yes. It is 123,456.

Bobbym - 90

If Gangnam style were a country (by no. of views), what rank is it?

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