Jump to content
BrainDen.com - Brain Teasers
  • 0

some 5 minute brain teasers


Go to solution Solved by bonanova,

Question

1. if all borks are grogs, and all grogs are snorts, are all snorts borks?

2. prove that GCD(A,B) = GCD(A+B,A) = GCD(A+B,B)

3. how much water, approximately, would you need to cover all land on earth in 3 feet of snow?

4. whats the shortest distance between any two points on a globe? A) straight line B) curved line

5. and just to be silly: what's the speed of dark?

 

 

Link to post
Share on other sites

1 answer to this question

Recommended Posts

  • 0
  • Solution

  1. No
     
  2. Let  f = GCD (A, B) so that A = f a and B = f b where GCD (a, b) = 1.
    Then (A+B) = f (a+b).
    GCD (A+B, A) = f GCD (a+b, a) = f  = f GCD (a+b, b) = GCD (A+B, B) = GCD (A, B).
     
  3. Approximately,
    R ~ 4000 mi;
    land area ~ (3/10)(4) pi R2 sq miles;
    3' of snow ~ 3" of water = 3/(12x5280) miles of water.
    Do the math: (land area) x (water depth) cubic miles of water would be needed..
     
  4. It depends.
    A) if "on a globe" refers just to the points then the distance between them is the length of a straight line;
    B) if "on a globe" refers to the distance then the distance on the globe's surface is the length of a curved line.
     
  5. The speed of light.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...