You’ve just received a secret coded message:

AD, BA, BH, CE, DB, DI, EF

You know it follows a pattern, but can you work out what pair of letters come next?

Scroll down for the answer!

## Brainteaser answer

You might have noticed that the first letter in each term is further along the alphabet. This could be considered a clue. And what if the pairs of letters represented numbers?

You can convert the letters to numbers using a simple substitution cypher:

A = 1, B = 2, C = 3 and so on.

This gives us the sequence:

14, 21, 28, 35, 42, 49, 56

You might notice that they’re all multiples of seven! That means the next number in the sequence is 63.

Taking it back through the substitution code, we get the answer, FC.

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