1+2+3+4+5-6-7+8-9= 1

1+2-3-4+5-6+7+8-9= 1

1000= 1+2+4+8+ 16+32+64+ 128+256+4 1 1

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1 The sum of the three prime numbers is 86, and the prime number is-

There must be an even prime number 2, and the remaining two add up to 84.

Can be 2+4 1+43, 2+37+47. ...

4。 There are six playing cards, all facing up. Turn five cards at a time How many times can you refuse them?

Flip 6 times, the first time without flipping 1, the second time without flipping the second time ... the sixth time without turning the sixth time.

So each photo was turned over five times, down.

6。 9 cups up, can you turn 4 cups down every time? Why?

I can't. To pour it all, each cup should be turned odd times, and the total number of cups should be turned odd times.

But turning four cups at a time is even, so no matter how many times I turn them, I always turn the cups even, which is contradictory.

9。 At the banquet, the guests shook hands with each other. Is the number of handshakes odd or even?

You mean the sum of people shaking hands, right? Even number.

Every time you shake hands, two people remember to shake hands by themselves. So the total is even.

1 1。 What is the power of odd-even classification 2 +3 and 7 and 9 in 2008? How many powers of 2 are even and adding 3 is odd.

7 is an odd number

How many powers of 9 are odd?