# On what basis have I split the alphabet into 4 sets?

I have split the 26 letters of the alphabet into 4 sets. Here they are:

Set 1: $F G J L N P Q R S Z$
Set 2: $A M T U V W Y$
Set 3: $B C D E K$
Set 4: $H I O X$

Can you determine on what basis have I split them?

• N, S, Z could form a set of their own. Jan 27 '15 at 11:16
• @FlorianF I was actually thinking the same, which caused me to hesitate about my answer, until I noticed what I was missing with those. But yeah, they should have had their own. Jan 27 '15 at 11:17

## 1 Answer

My guess:

I think you have split them based on symmetry. The first group has no real symmetry, while the second group can be divided by drawing a line from top to bottom. The third group can be splitted by drawing a horizontal line from left to right, and the last group can be divided using either a vertical or horizontal line.

• But N,S, and Z is symmetrical over a point in the middle. Jan 29 '15 at 14:39
• @Taemyr I know - but they are not symmetrical by drawing a line either horizontally or vertically: Therefore I said that the first group has no real symmetry. Jan 29 '15 at 14:42
• @KevinVoorn What you mean to say is that they have no reflectional symmetry. Jan 29 '15 at 16:11
• @Otaia Exactly, English is not my native language :3 Jan 29 '15 at 16:15