in reply to Re^5: If CAPTCHA isn't the answer. What is?
in thread If CAPTCHA isn't the answer. What is?

Indeed 

1/10 * C(9,0) +
1/10 * C(9,1) +
1/10 * C(9,2) +
1/10 * C(9,3) +
1/10 * C(9,4) +
1/10 * C(9,5) +
1/10 * C(9,6) +
1/10 * C(9,7) +
1/10 * C(9,8) +
1/10 * C(9,9) = 1/10 * 2 * (1 + 9 + 36 + 336 + 4536)
              = 983.6

[download]

1 in 84 becomes 1 in 983.6

On the other hand, it makes it harder on the user. People will be second guessing themselves.

In Section Meditations