Are the security questions for registration necessary

[metulburr]

I could do leet code, but a simplified version

What does f0ur plu5 51x equal to?

or 

What does f0ur plus six equal to?

or 

What does f0ur plus 6 equal to?

or could just write out in hopes they know

f0ur plus 6

I would like a more complex math, but i think some people would get the order of operations wrong. 

EDIT:
I enabled recaptcha. The default was actually regular captcha. So as long as that works fine, i guess there is no point to complex questions. I also disabled the research python questions and added simple math questions.