well, it is not so hard to program spambot, which can parse the string and calculate the answer...
2009/7/20 Jay Dan <[email protected]> > To ensure that the response is not generated by a computer. The process > usually involves one computer (a server) asking a user to complete a simple > test which the computer is able to generate and grade. Because other > computers are unable to solve the random math equation, any user entering a > correct solution is presumed to be human. It can also be treated as is a > type of challenge-response test. > > On Sat, Jul 18, 2009 at 6:14 PM, Anand <[email protected]> wrote: > >> >> hi, >> >> if see some site like fields in registration >> >> * (Spam protection) What is the sum of 15 + 17? >> >> Human check >> Some simple math 1+19 >> >> Why want to like this ?,if u know this >> > > > > -- > Jay >
