Brain teaser for the week 20200808 每周烧次脑
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let's get to today's mind-boggling puzzle!
Difficulty level: ✮ ✮ ✮ ✮ ✮
One segment of the game show Let's Make a Deal had three doors - behind one door was a new car and behind each of the other two was a goat. The contestant would win whatever was behind the door he or she chose.
Let's Make a Deal 中有一段剧情，说三个门后面分别有一辆新车，和两只山羊；选手选择任何一扇门打开，都要么会得到一辆车，要么是一只羊。
The contestant chose one of the three doors, but before it was opened, the host opened up a different door that had a goat behind it.
现在假设，一名选手先选择了一扇门，但在门被打开之前，主持人打开了剩下两扇门中的一扇，后面藏的是山羊。
In order to have the greatest chance of winning the car, should the contestant open the door that was his or her original choice or open the remaining door?
现在的问题是，从概率的角度看，这个选手该坚持之前选的那扇门，还是换剩下的一扇门，才能以更高的概率获得一辆新车？
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Answer to be disclosed at our
next episode of brain teaser
答案下期公布
Answer to the last week 上期答案 Brain teaser for the week 20200801 每周烧次脑:
12 rabbits and 23 chicken.
Please note that there is an unstated precondition - a rabbit has 4 feet, and a chick has two feet.
One of the smartest tricks to solve the question comes like this，
1, Ask all the animals to retract two of their feet. Those who have two feet, retract them all; who have four, put away two of them.
2, Then there should be 24 feet left, as 94-(35*2)=24.
To whom do you think those feet belong? Yes, the rabbits.
3, Thus we can have the number of rabbits, 24/2=12.
4, Then we can have the number of the chicken, 35-12=23.
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