Poached eggs puzzle only 20% of smart people solve! what about you?

Even if you're a smart person, you're not sure you've solved this puzzle.

Puzzle helps to train the brain - this is probably already known. And today, we will come up with a rather "tricky" puzzle that requires you to think logically.

Even if you are an intelligent person, it is unlikely to solve this puzzle. Try it!

Question:

A scholar always wanted to do everything perfectly. His breakfast has 1 egg, boiled in exactly 15 minutes.

However, he only has 2 hourglass: 1 11 minute, 1 7 minute. Ask how do you calculate the exact time it takes to boil eggs?

How to boil eggs exactly in 15 minutes?

Think about it. If not, please see the answer below.

Answer:

First, let both hourglass flow!

After the clock 7 minutes runs out, turn it over and start boiling the eggs.

At this time, the big watch will be 11 - 7 = 4 minutes. Now wait for the big clock to run out of sand and turn it over, you'll have an accurate time of 11 + 4 = 15 minutes.

However, this is not the only answer. If there are other answers, please leave a comment.

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