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 Hi I have seen the same question asked a few times on your site but they left out a bit.... OK I have a push button lock (the numbers entered does not have a start and end i.e. 1234 = 4321 or 2341 = 3241 ...) So if it is a 4 digit code and you have 10 buttons (0 to 9) there should be 5040 (?) possibilities and how would I list these unique combinations Kind Regards Werner

Werner, we have two responses for you.

Hi Werner,

If you look at the response I sent to Darrin and Kevin for a similar questions you will see that 5040 is the number of 4 digit arrangements using the digits 0, 1, 2, ..., 9. Mathematicians call these permutations and order is important so for example 1234, 1243, 2341 are all different. In my response to Kevin I showed him that if order is not important, as in your question, the number of possibilities is 210. Mathematicians call these combinations. At the end of my response to Darrin I showed him how to list all the three digit combinations. You can extend this to list all four digit combinations.

Penny

Werner, here are the 210. We listed the 5040 where order does matter in this reply to Kathy.


0123    0124    0125    0126    0127    0128    0129

0134    0135    0136    0137    0138    0139    0145

0146    0147    0148    0149    0156    0157    0158

0159    0167    0168    0169    0178    0179    0189

0234    0235    0236    0237    0238    0239    0245

0246    0247    0248    0249    0256    0257    0258

0259    0267    0268    0269    0278    0279    0289

0345    0346    0347    0348    0349    0356    0357

0358    0359    0367    0368    0369    0378    0379

0389    0456    0457    0458    0459    0467    0468

0469    0478    0479    0489    0567    0568    0569

0578    0579    0589    0678    0679    0689    0789

1234    1235    1236    1237    1238    1239    1245

1246    1247    1248    1249    1256    1257    1258

1259    1267    1268    1269    1278    1279    1289

1345    1346    1347    1348    1349    1356    1357

1358    1359    1367    1368    1369    1378    1379

1389    1456    1457    1458    1459    1467    1468

1469    1478    1479    1489    1567    1568    1569

1578    1579    1589    1678    1679    1689    1789

2345    2346    2347    2348    2349    2356    2357

2358    2359    2367    2368    2369    2378    2379

2389    2456    2457    2458    2459    2467    2468

2469    2478    2479    2489    2567    2568    2569

2578    2579    2589    2678    2679    2689    2789

3456    3457    3458    3459    3467    3468    3469

3478    3479    3489    3567    3568    3569    3578

3579    3589    3678    3679    3689    3789    4567

4568    4569    4578    4579    4589    4678    4679

4689    4789    5678    5679    5689    5789    6789



Stephen La Rocque.>

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