| The Math Marathon! | |
|
+3Nyx herefishyfishy1 isabella2296 7 posters |
Author | Message |
---|
isabella2296 Admin
Number of posts : 45 Location : You'd really like to know, wouldn't you? Registration date : 2008-08-16
| Subject: The Math Marathon! Sat Aug 16, 2008 8:14 am | |
| We all love marathons!
Problem 1:
Express the absolute value of the difference of 0.3636363636... and 0.36 as a common fraction. | |
|
| |
herefishyfishy1 Developer
Number of posts : 36 Age : 28 Location : An insignificant little blue-green planet 93 million miles from the sun Sol. Registration date : 2008-08-16
| Subject: Re: The Math Marathon! Sat Aug 16, 2008 8:18 am | |
| 0.363636363636= 4/11. Therefore, 0.363636363636-0.36=0.003636363636=4/1100. | |
|
| |
isabella2296 Admin
Number of posts : 45 Location : You'd really like to know, wouldn't you? Registration date : 2008-08-16
| Subject: Re: The Math Marathon! Sat Aug 16, 2008 8:19 am | |
| Rules: 1) You must show solutions. 2) You must post a new problem after solving. | |
|
| |
herefishyfishy1 Developer
Number of posts : 36 Age : 28 Location : An insignificant little blue-green planet 93 million miles from the sun Sol. Registration date : 2008-08-16
| Subject: Re: The Math Marathon! Sat Aug 16, 2008 8:29 am | |
| OK... then what is 1/(sqrt 11+sqrt 10)+1/(sqrt 10+sqrt 9)+1/(sqrt 9+sqrt 8 )+1/(sqrt 8+sqrt 7)+...+1/(sqrt 2+sqrt 1)
Yeah, I know it's the oldest problem in the world.
As for my solution,
.36363636... is the same as .3636363636.../.99999999... because the .9999999 is equal to 1. Therefore, it is equal to 36/99 or 4/11. .3636363636...-.36 is the same thing as .003636363636 which is simply 1/100 of 4/11, or 4/1100. | |
|
| |
Nyx Starting Member
Number of posts : 13 Location : stalker -_- Registration date : 2008-08-17
| Subject: Re: The Math Marathon! Tue Aug 19, 2008 1:17 pm | |
| - herefishyfishy1 wrote:
- OK... then what is 1/(sqrt 11+sqrt 10)+1/(sqrt 10+sqrt 9)+1/(sqrt 9+sqrt 8 )+1/(sqrt 8+sqrt 7)+...+1/(sqrt 2+sqrt 1)
Yeah, I know it's the oldest problem in the world. the ans is sqrt(11) - 1 because (and plz correct me if i'm mistaken) 1/(sqrt2 +1) = sqrt(2) - 1 because u multiply by the congegate 1/(sqrt3+sqrt2) = sqrt(3) - sqrt(2) therefore you have so far sqrt(3)-sqrt(2)+sqrt(2)-1 now u c that u can cross out the sqrt(2)'s getting sqrt(3)-1 now from this u can imply that the pattern will continue so everything crosses out except sqrt(11) and -1 therefore sqrt(11)-1 (o and i no i didn't go very far in the congegate multiplying and pattern part but u'll c that it's true) and i'll get back to you on a new question in a little bit | |
|
| |
FantasyLover Starting Member
Number of posts : 8 Location : Fantasy World Registration date : 2008-08-24
| Subject: Re: The Math Marathon! Mon Aug 25, 2008 11:48 am | |
|
4/37=0.abcabcabcabc...
Find a+b+c.
| |
|
| |
isabella2296 Admin
Number of posts : 45 Location : You'd really like to know, wouldn't you? Registration date : 2008-08-16
| Subject: Re: The Math Marathon! Tue Aug 26, 2008 11:43 am | |
| 1+0+8 = 9.
Sally sells 20 apples for 5 dollars. Bob sells 10 apples for 99 cents. Who has the better price? | |
|
| |
Dojo Admin
Number of posts : 154 Location : Probably somewhere near a computer Registration date : 2008-08-12
| Subject: Re: The Math Marathon! Tue Aug 26, 2008 11:29 pm | |
| Bob has the better deal. Divide into | |
|
| |
FantasyLover Starting Member
Number of posts : 8 Location : Fantasy World Registration date : 2008-08-24
| Subject: Re: The Math Marathon! Wed Aug 27, 2008 7:48 am | |
| x^2+2x+1.
Factor x^3-3x^2+3x-1 | |
|
| |
AIME15 Hardcore TMF user
Number of posts : 163 Age : 27 Location : Pleasanton, CA Registration date : 2008-08-13
| Subject: Re: The Math Marathon! Wed Aug 27, 2008 5:53 pm | |
| (x-1)^3? I'm not sure...so i wont post a new problem. | |
|
| |
FantasyLover Starting Member
Number of posts : 8 Location : Fantasy World Registration date : 2008-08-24
| Subject: Re: The Math Marathon! Wed Aug 27, 2008 7:16 pm | |
| yep, thats right. Find the difference between 0.369369369369369.... and 0.363636363636... | |
|
| |
ternary0210 School Math Nerd
Number of posts : 41 Age : 26 Registration date : 2008-08-17
| Subject: Re: The Math Marathon! Mon Sep 08, 2008 4:50 pm | |
| 4/27 Find ||3+4i|+i|6+6sqrt(3)i||, factor 6x^2+23x+21, add the coefficents, and add to the first one. | |
|
| |
Sponsored content
| Subject: Re: The Math Marathon! | |
| |
|
| |
| The Math Marathon! | |
|