A photo that looks like a set of triplets has caused confusion the world over, because despite the youthfulness of all three - one is the mother.

American teenager Kaylan Mahomes took a selfie in a car with her twin, Kyla, and their mother, the caption saying "Mom, twin and me."

But the three look identical, and figuring out which one is the mother has caused debate and confusion.

Kaylan posted the photo on January 28, so far the photo has been retweeted more than 19,000 times and received more than 31,000 likes, and has been shared and reported on in major media outlets.

CNN reports the three are from Indianapolis.

They have also posted a video to Instagram - also in the car, which gives away which one is the mother

The caption states  "When your mom thinks it's a picture ... lol #whosthemom?" after the three hold poses but all erupt into laughter when one of them seems to realises she was actually being videotaped.