+0  
 
+4
153
14
avatar+1088 

 

Find the value of the sum 

 

 

 Feb 23, 2020
 #1
avatar+109806 
+1

Are they combination maths or vectors?

 Feb 23, 2020
 #2
avatar+1088 
+1

I'm pretty sure it is 

 

 

 Feb 23, 2020
 #3
avatar+109806 
+1

Why did you get a point for that?

ok it is combination maths.

You can do it on your calculator.

 

13 nCr 0 + 13 nCr 1 + etc

 Feb 23, 2020
 #4
avatar
-2

xxxxxxxxxx

 Feb 23, 2020
edited by Guest  Feb 23, 2020
 #5
avatar+1088 
+4

I was trying to solve this problem without a calculator, and I was wondering if there was a trick, so I found this:

 

This sum consists of terms from the 13th row of Pascal's Triangle. We know the sum of the entire row is

 

 

Our sum consists only of the first half of those terms. Since Pascal's Triangle is symmetric, the sum of the terms in the first half of the row is equal to half the sum of the whole row's terms:

 

 Feb 23, 2020
 #6
avatar+1088 
+9

And also, Guest, I'm not sure why you deleted your answer, but if you were trying to hide it for some reason, I still saw your answer.

 Feb 23, 2020
edited by SpongeBobRules24  Feb 23, 2020
 #7
avatar+109806 
0

Well if you know how to do it on the calculator and you wanted to know how to do it by hand you should have stated that in your question and not wasted people's time.

You should also have given the calculator answer so that people could easily see if their answer was correct.

 

Let's have a look at it again.

 

The first term is 1, you should automatically know that

The second term is 13 you should know that too.

You can work the rest out by hand but it is messy.

 

there are 14 terms in the entire Pascal triangle row.

You have half the row and it is symmetrical

If the sum of the entire row is 2^13 as you say (I did not know that - You could/should have mentioned this in your original question.

Then the sum of your terms is half that = 2^12

 

If I had read your last response properly I would know that you already worked this out. 

I wasted my own time it was not your fault this time.

 

Isn't it great when you work things out for yourself !

Good work!

 Feb 23, 2020
 #8
avatar+1088 
+10

Why are you so mad, I just simply forgot to state something. I wouldn't have asked this question if I had a calculator.

 Feb 24, 2020
edited by SpongeBobRules24  Feb 24, 2020
 #9
avatar+109806 
-1

I am not mad. I congratulated you for working it out on your own.

And I stated that I was a goose for not realizing earlier that you had done so.

 

However, we are not mindreaders.

We do not know why you ask a question or what your problem with a question is if you do not tell us.

And we do not know what you already understand about the question if you do not tell us.

 

I did not even know if it was intended as a combination question until I asked you!

 

Hence you wasted my time as well as your own.

 

Hang on a bit. You said you asked because you did not have a calculator. This IS a calculator site.

Who is the goose this time?

Hint: It is not me.

Melody  Feb 24, 2020
 #10
avatar+1088 
+10

You know what, I'm not sure how you have the most likes on this website, but I really want to see CPhill beat you.

 Feb 26, 2020
 #11
avatar
-1

She can guve herself points

Guest Feb 27, 2020
 #12
avatar+1088 
+9

Wow, my wish actually came true, CPhill did beat you.

 Feb 28, 2020
 #13
avatar
-2

Well congrats to CPhill. It only took him seven years! 

You are a piece of fuckingshit Spongeboob.

You like to soak up the toxic waste at the bottom of the sea. That's where you belong and that's where you'll stay.

Guest Feb 29, 2020
 #14
avatar+1088 
+9

Actually, when I was a guest, CPhill was number one, and that was not seven years ago, and that toxic waste at the ocean is thanks to you, so how about you go clean it up.

 Feb 29, 2020
edited by SpongeBobRules24  Mar 1, 2020

8 Online Users

avatar
avatar