People have been left scratching their heads over a brainteaser designed to weed out ‘geniuses’ from the average folk.
If you can solve it correctly, and within a short timeframe, you likely have a high IQ and could be a great person to have around when a crisis strikes.
Taking to Reddit to share the brainteaser, a user said: “Four people (A,B,C,D) want to cross a bridge. It’s too dark, so they have to cross a bridge with a flashlight.
“The bridge is too old, so only two people can cross it at the same time. They only have one flashlight. They each take 1,2,5 and 10 minutes to cross the bridge, and they always go with the slower person’s pace (if A and B are crossing, it’ll take 2 minutes).
“What’s the fastest way for them to cross the bridge?”
Providing a clue, the user set out boundaries to the question, saying “no going around using the flashlight from the other side of the bridge or anything”.
For those struggling, they also state the answer is not 19 minutes.
Commenting on the brainteaser, one user said: “12 minutes – A and B swim across and use the flashlight to light the way for C and D.”
Another user added: “5 minutes? Person A carries person D on their back across the bridge and walks back. Does this for persons B and C as well. Would that work?”
A third user said: “1 minute. A carries B, C and D on his back.” One more user added: “Wow. I had to actually visually map it all out before that made sense to me.”
Coming through with the answer, another user said: “Send A & B across first. That’s 2 minutes. Send A back. That’s 1 minute. Send C & D across. That’s 10 minutes. Send B back. That’s 2 minutes. Send A & B back across. That’s 2 minutes. 2+1+10+2+2=17.”
