Re: [其他] 五個4,沒括號要怎麼變成16

[newversion (海納百川天下歸心)]

※ 引述《Mojear (穆傑爾)》之銘言：
: 數學問題:五個四，加減乘除都可，但是不可以用括弧，結果答案為十六
: 想了很久,好像湊不出答案
: 只好上來集思廣益...
: 應該有答案吧!不然覺得被唬了= =

無解，以下是所有可能，沒有一個是16

4+4+4+4+4 = 20  4+4+4+4-4 = 12  4+4+4+4*4 = 28  4+4+4+4/4 = 13
4+4+4-4+4 = 12  4+4+4-4-4 = 4  4+4+4-4*4 = -4  4+4+4-4/4 = 11
4+4+4*4+4 = 28  4+4+4*4-4 = 20  4+4+4*4*4 = 72  4+4+4*4/4 = 12
4+4+4/4+4 = 13  4+4+4/4-4 = 5  4+4+4/4*4 = 12  4+4+4/4/4 = 8.25
4+4-4+4+4 = 12  4+4-4+4-4 = 4  4+4-4+4*4 = 20  4+4-4+4/4 = 5
4+4-4-4+4 = 4  4+4-4-4-4 = -4  4+4-4-4*4 = -12  4+4-4-4/4 = 3
4+4-4*4+4 = -4  4+4-4*4-4 = -12  4+4-4*4*4 = -56  4+4-4*4/4 = 4
4+4-4/4+4 = 11  4+4-4/4-4 = 3  4+4-4/4*4 = 4  4+4-4/4/4 = 7.75
4+4*4+4+4 = 28  4+4*4+4-4 = 20  4+4*4+4*4 = 36  4+4*4+4/4 = 21
4+4*4-4+4 = 20  4+4*4-4-4 = 12  4+4*4-4*4 = 4  4+4*4-4/4 = 19
4+4*4*4+4 = 72  4+4*4*4-4 = 64  4+4*4*4*4 = 260  4+4*4*4/4 = 20
4+4*4/4+4 = 12  4+4*4/4-4 = 4  4+4*4/4*4 = 20  4+4*4/4/4 = 5
4+4/4+4+4 = 13  4+4/4+4-4 = 5  4+4/4+4*4 = 21  4+4/4+4/4 = 6
4+4/4-4+4 = 5  4+4/4-4-4 = -3  4+4/4-4*4 = -11  4+4/4-4/4 = 4
4+4/4*4+4 = 12  4+4/4*4-4 = 4  4+4/4*4*4 = 20  4+4/4*4/4 = 5
4+4/4/4+4 = 8.25  4+4/4/4-4 = 0.25  4+4/4/4*4 = 5  4+4/4/4/4 = 4.0625
4-4+4+4+4 = 12  4-4+4+4-4 = 4  4-4+4+4*4 = 20  4-4+4+4/4 = 5
4-4+4-4+4 = 4  4-4+4-4-4 = -4  4-4+4-4*4 = -12  4-4+4-4/4 = 3
4-4+4*4+4 = 20  4-4+4*4-4 = 12  4-4+4*4*4 = 64  4-4+4*4/4 = 4
4-4+4/4+4 = 5  4-4+4/4-4 = -3  4-4+4/4*4 = 4  4-4+4/4/4 = 0.25
4-4-4+4+4 = 4  4-4-4+4-4 = -4  4-4-4+4*4 = 12  4-4-4+4/4 = -3
4-4-4-4+4 = -4  4-4-4-4-4 = -12  4-4-4-4*4 = -20  4-4-4-4/4 = -5
4-4-4*4+4 = -12  4-4-4*4-4 = -20  4-4-4*4*4 = -64  4-4-4*4/4 = -4
4-4-4/4+4 = 3  4-4-4/4-4 = -5  4-4-4/4*4 = -4  4-4-4/4/4 = -0.25
4-4*4+4+4 = -4  4-4*4+4-4 = -12  4-4*4+4*4 = 4  4-4*4+4/4 = -11
4-4*4-4+4 = -12  4-4*4-4-4 = -20  4-4*4-4*4 = -28  4-4*4-4/4 = -13
4-4*4*4+4 = -56  4-4*4*4-4 = -64  4-4*4*4*4 = -252  4-4*4*4/4 = -12
4-4*4/4+4 = 4  4-4*4/4-4 = -4  4-4*4/4*4 = -12  4-4*4/4/4 = 3
4-4/4+4+4 = 11  4-4/4+4-4 = 3  4-4/4+4*4 = 19  4-4/4+4/4 = 4
4-4/4-4+4 = 3  4-4/4-4-4 = -5  4-4/4-4*4 = -13  4-4/4-4/4 = 2
4-4/4*4+4 = 4  4-4/4*4-4 = -4  4-4/4*4*4 = -12  4-4/4*4/4 = 3
4-4/4/4+4 = 7.75  4-4/4/4-4 = -0.25  4-4/4/4*4 = 3  4-4/4/4/4 = 3.9375
4*4+4+4+4 = 28  4*4+4+4-4 = 20  4*4+4+4*4 = 36  4*4+4+4/4 = 21
4*4+4-4+4 = 20  4*4+4-4-4 = 12  4*4+4-4*4 = 4  4*4+4-4/4 = 19
4*4+4*4+4 = 36  4*4+4*4-4 = 28  4*4+4*4*4 = 80  4*4+4*4/4 = 20
4*4+4/4+4 = 21  4*4+4/4-4 = 13  4*4+4/4*4 = 20  4*4+4/4/4 = 16.25
4*4-4+4+4 = 20  4*4-4+4-4 = 12  4*4-4+4*4 = 28  4*4-4+4/4 = 13
4*4-4-4+4 = 12  4*4-4-4-4 = 4  4*4-4-4*4 = -4  4*4-4-4/4 = 11
4*4-4*4+4 = 4  4*4-4*4-4 = -4  4*4-4*4*4 = -48  4*4-4*4/4 = 12
4*4-4/4+4 = 19  4*4-4/4-4 = 11  4*4-4/4*4 = 12  4*4-4/4/4 = 15.75
4*4*4+4+4 = 72  4*4*4+4-4 = 64  4*4*4+4*4 = 80  4*4*4+4/4 = 65
4*4*4-4+4 = 64  4*4*4-4-4 = 56  4*4*4-4*4 = 48  4*4*4-4/4 = 63
4*4*4*4+4 = 260  4*4*4*4-4 = 252  4*4*4*4*4 = 1024  4*4*4*4/4 = 64
4*4*4/4+4 = 20  4*4*4/4-4 = 12  4*4*4/4*4 = 64  4*4*4/4/4 = 4
4*4/4+4+4 = 12  4*4/4+4-4 = 4  4*4/4+4*4 = 20  4*4/4+4/4 = 5
4*4/4-4+4 = 4  4*4/4-4-4 = -4  4*4/4-4*4 = -12  4*4/4-4/4 = 3
4*4/4*4+4 = 20  4*4/4*4-4 = 12  4*4/4*4*4 = 64  4*4/4*4/4 = 4
4*4/4/4+4 = 5  4*4/4/4-4 = -3  4*4/4/4*4 = 4  4*4/4/4/4 = 0.25
4/4+4+4+4 = 13  4/4+4+4-4 = 5  4/4+4+4*4 = 21  4/4+4+4/4 = 6
4/4+4-4+4 = 5  4/4+4-4-4 = -3  4/4+4-4*4 = -11  4/4+4-4/4 = 4
4/4+4*4+4 = 21  4/4+4*4-4 = 13  4/4+4*4*4 = 65  4/4+4*4/4 = 5
4/4+4/4+4 = 6  4/4+4/4-4 = -2  4/4+4/4*4 = 5  4/4+4/4/4 = 1.25
4/4-4+4+4 = 5  4/4-4+4-4 = -3  4/4-4+4*4 = 13  4/4-4+4/4 = -2
4/4-4-4+4 = -3  4/4-4-4-4 = -11  4/4-4-4*4 = -19  4/4-4-4/4 = -4
4/4-4*4+4 = -11  4/4-4*4-4 = -19  4/4-4*4*4 = -63  4/4-4*4/4 = -3
4/4-4/4+4 = 4  4/4-4/4-4 = -4  4/4-4/4*4 = -3  4/4-4/4/4 = 0.75
4/4*4+4+4 = 12  4/4*4+4-4 = 4  4/4*4+4*4 = 20  4/4*4+4/4 = 5
4/4*4-4+4 = 4  4/4*4-4-4 = -4  4/4*4-4*4 = -12  4/4*4-4/4 = 3
4/4*4*4+4 = 20  4/4*4*4-4 = 12  4/4*4*4*4 = 64  4/4*4*4/4 = 4
4/4*4/4+4 = 5  4/4*4/4-4 = -3  4/4*4/4*4 = 4  4/4*4/4/4 = 0.25
4/4/4+4+4 = 8.25  4/4/4+4-4 = 0.25  4/4/4+4*4 = 16.25  4/4/4+4/4 = 1.25
4/4/4-4+4 = 0.25  4/4/4-4-4 = -7.75  4/4/4-4*4 = -15.75  4/4/4-4/4 = -0.75
4/4/4*4+4 = 5  4/4/4*4-4 = -3  4/4/4*4*4 = 4  4/4/4*4/4 = 0.25
4/4/4/4+4 = 4.0625  4/4/4/4-4 = -3.9375  4/4/4/4*4 = 0.25  4/4/4/4/4 = 0.015625



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