A user answered a question, gave the formula to the poster, and left it to the poster to calculate the numerical answer. Moderator andselisk then cited the meta-post Hint answers revisited and indicated that the answer wasn't good enough. I don't remember that discussion, nor ever having seen any...

If carbon's $\mathrm{sp^2}$ orbital is overlapped with hydrogen's $\mathrm{s},$ then why it is $\mathrm{sp^2}$ and why not $\mathrm{sp^2s}?$