Lily Love

come to school....

Still so familiar.

Suddenly, an announcement appeared in front of him.

"Why, why is the monthly exam so early, are you okay, the principal."

Perhaps, in the language of others, you can know that the monthly exam has been advanced.

It turns out that tomorrow the headmaster has to leave for a few weeks, and the monthly exam will be delayed, so...

At first glance, what is the monthly exam today, it is really hard to guard against!

"Oops, I, I didn't review it." Lily sighed, but more than one was complaining, and there were 1, 2, 3, 4... 19... Anyway, the number is too many to count .

"Dingling bell, the monthly exam will start in 10 minutes, dingling bell, the monthly exam will start..." the radio kept repeating.

The crowd was crowded, and they all rushed to the teaching building.

------------------------------------ 10 minutes passed ---------- -----------------------------------

The monthly exam begins!

Seeing the first question, Lily was stunned, it was so difficult, it would kill her!

"Forget it, let's do other things first."

Fortunately, Lily couldn't be troubled by other things, so I finished writing smoothly!

"What should I do? This question is the only thing left, no... My life's wisdom will be defeated by this question! don't want."

Watching the time rush by, Lily became even more anxious.

Look at your watch, only 10 minutes to go! ! ! ! ! !

"What to do? What to do? What to do!"

Lily scratched her head.

"Huh? It seems to be like this."

Lily wrote with her own thoughts and figured it out!

(Let’s take a look at that question.)

It takes an hour to burn an uneven rope, how to judge half an hour by it?

To burn an uneven rope, it takes a total of 1 hour to burn from the beginning to the end.Now there are several ropes of the same material, how to time an hour and 15 minutes by burning the ropes?

Answer: Burning from both ends can be determined for half an hour.First take one and burn it at both ends, and one at one end.When the two ends are burnt, start timing and light the other one, burn it for 15 minutes, and then light one for 1 hour, it will be OK

??

(Answer... I don’t know if it’s right or not) Maybe——

It should be to burn both ends of a rope, one at one end, and after the two ends are burned, the remaining end of one end is lit, and after burning, one rope is burned at the other end.

Well... this question is very difficult for me...

Lily finished writing, almost at the same time, the time came.

"Okay, time is up, put down the pen and go out."

……

"It's so difficult, there is a question."

"Well, it's so difficult. Why does it take an hour to burn an uneven rope, how can it be used to judge half an hour? It takes an hour to burn an uneven rope from the beginning to the end. Now there are several Ropes of the same material, how to use the method of burning the rope to time an hour and 1 minutes? It’s so difficult, it’s too simple to die!”

"exactly."

"Hey."

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