### Brain Teasers

# 9 = 4

Complete the series. 9 = 4, 21 = 9, 22 = 9, 24 = 10, 8 = 5, 7 = 5, 99 = 10, 100 = 10, 16 = ?, 17 = ?

### Hint

Count carefully.### Answer

16 = 7 and 17 = 9. The number of letters in the spelling of 16 (sixteen) is 7 and that of 17 (seventeen) is 9.Hide Hint Show Hint Hide Answer Show Answer

## What Next?

View a Similar Brain Teaser...

If you become a registered user you can vote on this brain teaser, keep track of which ones you have seen, and even make your own.

### Solve a Puzzle

## Comments

also known as "4 is cosmic" - start with any number and go to the 'next' ie: 100 -> 10 -> 3 -> 5 -> 4 and you will always always end at 4.

Good one.

I don't get it.

the rule of 4 means you can start at any number and if you count characters down you will always end up at 4.

100 = One hundred = 10 = Ten = 3 = three = 5 = five = 4

100 = One hundred = 10 = Ten = 3 = three = 5 = five = 4

Best logic one I ever saw

To post a comment, please create an account and sign in.

## Follow Braingle!