The Math Forum

For anyone with a love of math
 
HomeHome  CalendarCalendar  GalleryGallery  FAQFAQ  SearchSearch  MemberlistMemberlist  UsergroupsUsergroups  RegisterRegister  Log in  

Share | 
 

 The Math Marathon!

View previous topic View next topic Go down 
AuthorMessage
isabella2296
Admin
Admin


Number of posts : 45
Location : You'd really like to know, wouldn't you?
Registration date : 2008-08-16

PostSubject: 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.
Back to top Go down
View user profile
herefishyfishy1
Developer
Developer


Number of posts : 36
Age : 22
Location : An insignificant little blue-green planet 93 million miles from the sun Sol.
Registration date : 2008-08-16

PostSubject: Re: The Math Marathon!   Sat Aug 16, 2008 8:18 am

0.363636363636= 4/11. Therefore, 0.363636363636-0.36=0.003636363636=4/1100.
Back to top Go down
View user profile
isabella2296
Admin
Admin


Number of posts : 45
Location : You'd really like to know, wouldn't you?
Registration date : 2008-08-16

PostSubject: 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.


Smile
Back to top Go down
View user profile
herefishyfishy1
Developer
Developer


Number of posts : 36
Age : 22
Location : An insignificant little blue-green planet 93 million miles from the sun Sol.
Registration date : 2008-08-16

PostSubject: 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.
Back to top Go down
View user profile
Nyx
Starting Member
Starting Member


Number of posts : 13
Location : stalker -_-
Registration date : 2008-08-17

PostSubject: 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
Back to top Go down
View user profile
FantasyLover
Starting Member
Starting Member
avatar

Number of posts : 8
Location : Fantasy World
Registration date : 2008-08-24

PostSubject: Re: The Math Marathon!   Mon Aug 25, 2008 11:48 am



4/37=0.abcabcabcabc...

Find a+b+c.
Back to top Go down
View user profile
isabella2296
Admin
Admin


Number of posts : 45
Location : You'd really like to know, wouldn't you?
Registration date : 2008-08-16

PostSubject: 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?
Back to top Go down
View user profile
Dojo
Admin
Admin
avatar

Number of posts : 154
Location : Probably somewhere near a computer
Registration date : 2008-08-12

PostSubject: Re: The Math Marathon!   Tue Aug 26, 2008 11:29 pm



Bob has the better deal.

Divide into

_________________
~Dojo
Back to top Go down
View user profile http://themathforum.forumotion.com
FantasyLover
Starting Member
Starting Member
avatar

Number of posts : 8
Location : Fantasy World
Registration date : 2008-08-24

PostSubject: Re: The Math Marathon!   Wed Aug 27, 2008 7:48 am

x^2+2x+1.

Factor x^3-3x^2+3x-1
Back to top Go down
View user profile
AIME15
Hardcore TMF user
Hardcore TMF user
avatar

Number of posts : 163
Age : 20
Location : Pleasanton, CA
Registration date : 2008-08-13

PostSubject: 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.

_________________
-AIME15, Moderator of Algebra Forum
Back to top Go down
View user profile
FantasyLover
Starting Member
Starting Member
avatar

Number of posts : 8
Location : Fantasy World
Registration date : 2008-08-24

PostSubject: Re: The Math Marathon!   Wed Aug 27, 2008 7:16 pm

yep, thats right.

Find the difference between 0.369369369369369.... and 0.363636363636...
Back to top Go down
View user profile
ternary0210
School Math Nerd
School Math Nerd


Number of posts : 41
Age : 19
Registration date : 2008-08-17

PostSubject: Re: The Math Marathon!   Mon Sep 08, 2008 4:50 pm

Nervous
4/27
Find ||3+4i|+i|6+6sqrt(3)i||, factor 6x^2+23x+21, add the coefficents, and add to the first one.
Back to top Go down
View user profile
Sponsored content




PostSubject: Re: The Math Marathon!   

Back to top Go down
 
The Math Marathon!
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» ALERT!! 2 EXPLOSIONS AT BOSTON MARATHON FINISH UPDATED UNBELIEVABLE!!!
» Keganjilan dan Kejanggalan Pada "Tragedi Bom Boston Marathon 2013? Memicu Konspirasi
» Frostbite Marathon Relay
» Wagga Wagga Marathon / Lake to Lagoon
» Heart Mini Marathon 2016

Permissions in this forum:You cannot reply to topics in this forum
The Math Forum :: Middle School Topics :: Problem Solving :: Marathons-
Jump to: