作者newversion (海納百川天下歸心)
看板Math
標題Re: [其他] 五個4,沒括號要怎麼變成16
時間Tue Jan 25 16:26:55 2011
※ 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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