Melody

921 Questions
34315 Answers

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Mathigon website

I just discovered a site called mathigon

https://mathigon.org/dashboard
read more ..

Melody Apr 2, 2022

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Reporting problems.

There are a number of people having problems at the moment.
If you lodge an error can you please give all relevant information that you can think of.
Where you are in the world - the city or the country - is often very important information. read more ..

Melody Mar 16, 2022

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How to make an empty rectangle in Latex

I just worked out how to make an empty box of various horizonal size easily in LaTex.
This is not a recommended method, but other methods that I have tried here have not worked.
This coding is really simple. Just put letters inside read more ..

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Melody Mar 15, 2022

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HAPPY ANNIVERSARY CHRIS! (CPhill)

I just realized that you became a member here exactly 8 years ago today!

It has been great to have you here all that time

off-topic

Melody Mar 13, 2022

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WELCOME BACK CPHILL !

Melody Feb 11, 2022

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Very interesting question. No high level maths required.

This question was posted a couple of days ago.
https://web2.0calc.com/questions/geometry_73561

I think it is really interesting. It looks much more difficult than it really needs to be. read more ..

Melody Feb 1, 2022

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Members have a better experience. Their questions get more attention.

Almost everyone is posting as a guest.
If you post as a member your questions will have a far greater chance of a timely and helpful response.
If you are a genuine learner and interact with us, you will become known and answerers will do read more ..

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Melody Jan 9, 2022

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HAPPY BIRTHDAY CHRIS!

Melody Dec 20, 2021

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Some guidelines for question askers.

Please note:
1) Ask only one question per post.
2) When asking a question talk about what you have tried for yourself. Then people will take you more seriously and will be more able and willing to help.
3) If you get an answer read more ..

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Melody Nov 4, 2021

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Remeniscing - a little historical humour.

I just found this old post that some of you, who have been around for a while, might find amusing.

https://web2.0calc.com/questions/look-at-the-new-leader-board

off-topic

Melody Oct 29, 2021

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(3 hours/ 12 braclets) * 50 braclets = 3/12*50 hours (the braclets cancel out.) Yes, you really can do this.

MelodyOct 8, 2013

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Well, in that case I think the answer would have to be irrational.
Good luck with the Beal Conjecture.
Thanks for getting back to me, I really appreciate it.

Do you know why you are not listed as a member?
I am just trying to work out how this site works.

MelodyOct 8, 2013

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You can use the fraction button or you can use the divide button.

MelodyOct 8, 2013

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I assume you mean 18% per year, and there are 12 months in a years, so what do you think the answer might be?

MelodyOct 8, 2013

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Is this a time?
It will be negative 16 seconds

MelodyOct 8, 2013

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Say you want to divide 2 by 4 ,
this would be the same as dividing (2*10) by (4*10) OR
this would be the same as dividing (2*7) by (4*7)
They all equal 1/2

you use this idea when you divide decimal (unless you use a calculator). You'd never use 7 just 10, or 100, or 1000 etc

Say you want to divide 0.2 by 0.005
I can't divide by 0.005 but if I multiply it by 1000, I can divide by 5
so
0.2/0.005 becomes (0.2*1000)/(0.005*1000) = 200/5 = 40

It is the one on the bottom that has to be a whole number. It is much easier to see what you are doing if you write your divisions as upright fractions. Where you can see the top and the bottom easily.
Do you know how to do 0.2*1000?

If you would like me to explain anything a bit better just let me know.
I hope I have been helpful.
There are 3 zeros and 1000 is a big number (bigger than 1) so you move the point 3 places in a direction to make the number bigger.

MelodyOct 8, 2013

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I'll give you a hint
first turn one pair into 4 and the other pair into 2 and then think about it.

MelodyOct 8, 2013

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It is just
12/30 *100 = 40%

MelodyOct 8, 2013

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7C5
Supermathexpert is correct !

7C5 = 7! / [(7-5)!*5!]
What I am trying to show is that the 5! is on the bottom.

= 1*2*3*4*5*6*7 / [(1*2) * (1*2*3*4*5)]
= 6*7 / 2
=21

If you are doing it on your calculator there is a button that looks like nCr

You put in 7 nCr 5
The C stands for combinations

If you have 7 different books on a book shelf, 7C5 gives you the number of different combinations of 5 books that you can choose.

It is used in probability all the time.
Both numbers have to be whole numbers and the second one cannot be bigger than the first or it will not make sense.
I hope that this helps.

MelodyOct 8, 2013

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Well,
x=6-y (from the first equation)
Substitute this into the second equation and it will all fall out nicely.
If that is not enough help just ask again.

MelodyOct 8, 2013