Boiling an egg might seem like an easy task, but a new riddle will make you question everything you thought you knew about getting the timing just right.

Challenging yourself to complete tricky puzzles and brain teasers can be a great way of giving your mind a proper workout, and as we all know, keeping your brain healthy is just as important as the rest of your body - even if you have to exercise the organ in a different way.

This new riddle is sure to give your brain the boost it needs to get you through the day, but it might make you never want to look at an egg again as you'll be scratching your head trying to work out the answer.

The riddle is said to be so tricky that only "really smart people" can solve it, according to Insider, who posted the quiz question on their website. The question reads: "If you have a seven-minute hourglass and an 11-minute hourglass, how can you boil an egg in exactly 15 minutes?"

It might seem simple on the surface, but it's harder than it looks. There's seemingly no way to make the two hourglasses perfectly time 15 minutes, as simply using each of them once will add up to 18 minutes. You also can't use the 7-minute timer twice, as this will leave you one minute short on 14, and two turns of the 11-minute timer will have your imaginary egg boiling dry after being left on the gas for 22 minutes.

Have you worked out how to do it yet? It requires a bit more thinking, but there is a fairly straightforward way to make the two hourglass timers give you the 15 minutes you're looking for. Keep reading to find out how.

Solution

Your first step for this puzzle should be to start both egg timers at once. Then, once seven minutes have elapsed and the smaller timer has run out, flip it over to start it again. Four minutes later, the 11-minute timer will have run out, and four minutes' worth of sand will have fallen through to the other side of the seven-minute timer.

At this point, 11 minutes have elapsed. Your final step then needs to be flipping over the seven-minute timer again. The timer will run for four minutes before it finishes, bringing you to a perfect time of 15 minutes.

Did you solve the puzzle? Let us know in the comments!