### Random Post

### Recent Posts

### Recent Comments

### Archives

### Categories

- article (11)
- enigma (1,367)
- misc (4)
- project euler (2)
- puzzle (90)
- puzzle# (48)
- site news (58)
- tantalizer (94)
- teaser (7)

### Site Stats

- 233,130 hits

Programming Enigma Puzzles

13 December 2011

Posted by on **From New Scientist #2797, 29th January 2011** [link]

This is Joe’s pyramid. Every stone is marked with a different one or two digit positive number.

Where a stone rests on two others, its number is the sum of the numbers marked on the two stones on which it rests.

What number is X?

[enigma1631]

%d bloggers like this:

This Python program runs in 815ms – I can get it down to 280ms by explicitly coding up the sums involved, but this is much neater.

Solution:X = 98.Another pyramid – I found two solutions, one bring a mirror image of the other, with X = 98 in both cases