A Conversation for The H2G2 Puzzle Network
Puzzle 8 - Four Fours
Icy North Posted Mar 14, 2005
Time to introduce factorials. n! = 1 * 2 * 3 * ... * n
Hence 4 factorial (notation 4!) = 1 * 2 * 3 * 4 = 24
4! - 4 - (4/4) = 19
Puzzle 8 - Four Fours
aka Bel - A87832164 Posted Mar 15, 2005
Icy, you said >>There is no restriction on which mathematical functions and operators you use with the four 4's.<<, so here goes :
(4² + 4²)- 4/4 = 31
4*4 + 4*4 = 32
Puzzle 8 - Four Fours
aka Bel - A87832164 Posted Mar 15, 2005
4² + 4² + 4/4 = 33
4! + 4 + 4 + SQRT(4) = 34
(4³ + 4 + SQRT(4))/ SQRT(4)= 35
(4³ + 4 + 4)/ SQRT(4)= 36
or
4! + 4² - SQRT(4) - SQRT(4) = 36
or
4*4 + 4² + 4 = 36
or
(4! + 4! +4!)/ SQRT(4)= 36
Still looking for a way to get 37 
Puzzle 8 - Four Fours
Icy North Posted Mar 15, 2005
Hi Bel,
I'm not sure we should be allowing all those little ²s and ³s!
I don't want to undo all your good work though, so shall we put a limit of ³ on indices?
Icy
Puzzle 8 - Four Fours
Icy North Posted Mar 15, 2005
And if we're allowing indices, we can have 4º = 1, which solves the problem with 37:
4² + 4² + 4 + 4º = 37
Puzzle 8 - Four Fours
aka Bel - A87832164 Posted Mar 15, 2005
Thanks, that's great. I think ³ must be the largest anyway, because there's no larger on my keyboard, and a 4 would not bring any advantage.
4! + 4*4 - SQRT(4) = 38
4³ - 4! - 4/4 = 39
4*4*4 - 4! = 40
Key: Complain about this post
Puzzle 8 - Four Fours
- 21: Icy North (Mar 14, 2005)
- 22: Icy North (Mar 14, 2005)
- 23: Icy North (Mar 14, 2005)
- 24: Icy North (Mar 14, 2005)
- 25: Icy North (Mar 14, 2005)
- 26: Icy North (Mar 14, 2005)
- 27: Icy North (Mar 14, 2005)
- 28: Icy North (Mar 14, 2005)
- 29: aka Bel - A87832164 (Mar 14, 2005)
- 30: aka Bel - A87832164 (Mar 14, 2005)
- 31: aka Bel - A87832164 (Mar 14, 2005)
- 32: Icy North (Mar 14, 2005)
- 33: Icy North (Mar 14, 2005)
- 34: aka Bel - A87832164 (Mar 15, 2005)
- 35: aka Bel - A87832164 (Mar 15, 2005)
- 36: aka Bel - A87832164 (Mar 15, 2005)
- 37: aka Bel - A87832164 (Mar 15, 2005)
- 38: Icy North (Mar 15, 2005)
- 39: Icy North (Mar 15, 2005)
- 40: aka Bel - A87832164 (Mar 15, 2005)
More Conversations for The H2G2 Puzzle Network
Write an Entry
"The Hitchhiker's Guide to the Galaxy is a wholly remarkable book. It has been compiled and recompiled many times and under many different editorships. It contains contributions from countless numbers of travellers and researchers."