Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: √ ∞ ≠ ≤ ≥ ≈ ⇒ ∈ Δ θ ∴ ∑ ∫ π -

Login

Username

Password

Not registered yet?

#1 2005-08-23 19:06:30

MathsIsFun
Administrator

Offline

Two emailed Puzzles

A visitor has asked me by email:

I need a solution for the below questions:

Can you write 31 by usingly only digit 3 five times?

Can you place 10 coins in a five straight lines each having four coins?


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman
 

#2 2005-08-23 20:38:24

mathsyperson
Moderator

Offline

Re: Two emailed Puzzles

Well, the second one is a star:

                            O

                O      O    O      O
           
                      O         O
                            O               
                    O              O

It would work if I could draw better, but you see what I mean.
The first one I'll have to think about.


Why did the vector cross the road?
It wanted to be normal.
 

#3 2005-08-23 20:44:12

MathsIsFun
Administrator

Offline

Re: Two emailed Puzzles

3^3 + 3 + 3/3 = 27 + 3 + 1 = 31

(That star would make a good logo !)


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman
 

#4 2005-08-24 20:53:23

wcy
Full Member

Offline

Re: Two emailed Puzzles

Another way:
33-3+3/3=33-3+1=31

 

#5 2005-08-24 21:29:09

mathsyperson
Moderator

Offline

Re: Two emailed Puzzles

Technically, the answer to both is 'yes'.


Why did the vector cross the road?
It wanted to be normal.
 

#6 2005-08-24 22:09:46

MathsIsFun
Administrator

Offline

Re: Two emailed Puzzles

And I thought the answer to both was 31 ... silly me.


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman
 

Board footer

Powered by FluxBB