Sandy Wood
Brain Game: Countdown
by Sandy Wood - September 15, 2008 - 6:30 AM

THE ANSWER:

In each case, the answer is FOUR. The next number in each sequence is the number of letters used to spelling out the previous number.

SEVENTEEN (9 letters) -> NINE (4 letters) -> FOUR
ONE (3 letters) -> THREE (5 letters) -> FIVE (4 letters) -> FOUR
TWENTY (6 letters) -> SIX (3 letters) -> THREE (5 letters) -> FIVE (4 letters) -> FOUR

They all get stuck on the number four, since its name has four letters.

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