YouTube user xmintyx shared a video of him and his girlfriend discussing a math riddle regarding the ages of two hypothetical brothers. Both were sincerely adamant enough in their responses that it's easy to be sympathetic to their two different explanations. But there is only one correct answer, and the girlfriend is very, very wrong.

"The big brother is four years old, the little brother is half his age. How old will the little brother be when the big brother is 100?" Mercifully, this woman was quickly able to see where she went wrong in her logic. Hopefully most people solved that riddle well before the girlfriend—and in much less time than it takes to find this egg in this frustrating egg hunt

Sources: h/t Neatorama