Brittany R. Nội dung chính I need to know how many passwords can be formed 4 Answers By Expert Tutorsthis is a permutation problem there are 26 letters of the alphabet you want 6-character passwords without repetition the first time you pick a letter, you pick from 26 letters the second time you pick a letter, you pick from 25 letters (no repetitions !) the third time you pick a letter, you pick from 24 letters, and so on the answer is 26*25*24*23*22*21=165,765,600 passwords Sky W. answered • 10/22/13 Patient and Knowledgeable Math Tutor This problem is VERY SIMILAR to the CD problem that I wrote an answer for. Order matters because if I type "faster" as my password, I can't type "astfre" which is all the same letters, but the order isn't correct, so it wont register as correct. How many options of letters do you have for the first letter->26, what about the 2nd-Well we used one already so there are 25 left to choose form. Third letter, 24 choices, 4th letter 23 choices, 5th->22 and 6th 21. _ _ _ _ _ _ Think of it like that. Those dashes are the places for your letters. 26 * 25 * 24 * 23* 22 * 21 Ellen S. answered • 10/22/13 Math and Writing Geek This problem comes from a fun little branch of mathematics called "combinatorics." Basically, they want to know how many different combinations you could make out of the letters of the alphabet, given that they're all lowercase and no repeats are allowed. So let's put six boxes on our piece of paper, one for each character in the password. Got that? _ _ _ _ _ _ Now, how many possible choices are there for the first character? We know the letters are all lowercase, so it would just be 26, since that's how many letters are in the alphabet. So the first character has 26 choices. Now, move on to the second character. Still 26 letters in the alphabet, but WAIT! We've already used one in the first position, and we know we can't repeat it. So now there are only 25 letters to choose from. Continue in this way to find the number of possibilities for each position in the password. You should end up with: _ _ _ _ _ _ 26 25 24 23 22 21 So now comes the fun part. If we know how many possibilities there are for each position in the password, we simply multiply them all together to get the total number of possible combinations. (There is a proof of why this works, but it's long and complicated so I won't get into it here.) Do that, and you'll get: 26 x 25 x 24 x 23 x 22 x 21 = 165,765,600 So there are 165,765,600 different password combinations using the parameters specified. Hope that helps! Vivian L. answered • 10/22/13 Microsoft Word/Excel/Outlook, essay composition, math; I LOVE TO TEACH Hi Brittany; Thank you for another great question! 26 x 25 x 24 x 23 x 22 x 21 You initially have 26 characters to select from. Then you have 25 characters to select from. Then you have 24 characters to select from. etc. Still looking for help? Get the right answer, fast.ORFind an Online Tutor Now Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.
How many 5 character passwords can be made using the letters A through Z?1 Expert Answer There are 26 letters in the English alphabet (a through z) and 10 digits (0 through 9). Thus for each of the five characters there are a total of 36 options. Each character is independent of the other characters. There are over 60 million possible passwords. How many 5 letter passwords can be formed?Since there are only 5 vowels, each of the letters in the password can be chosen from these 5 vowels. Therefore the answer is 5 to the fifth power which is 3125. However, if the password is case sensitive, then you actually have 10 choices for each character in your password which would give you 100,000 possibilities. How many 3 letter passwords can be made using the letters A through Z if?There are 15,600 different 3-letter passwords, with no letters repeating, that can be made using the letters a through z. A 3-letter password, with no letters repeating, using the letters a through z, is simply a permutation of 3 letters taken from the alphabet, which has 26 letters. How many passwords are possible if no character can be repeated?If no characters can be repeated, then there are 36 choices for the first, 35 for the second, 34 for the third, 33 for the fourth, 32 for the fifth, and 31 for the sixth. The total number of passwords would be 36 × 35 × 34 × 33 × 32 × 31 or 1,402,410,240. or 308,915,776 possible passwords. How many 5 letter words can be formed if repetitions are allowed?If repetition is allowed, the number of words we can form = 4*4*4*4*4 = 1024. (This is because, when repetition is allowed, we can put any of the four unique alphabets at each of the five positions.) If repetition is not allowed, the number of words we can form = 5!/2! = 60.
How many 5 letter passwords are possible?Therefore the answer is 5 to the fifth power which is 3125. However, if the password is case sensitive, then you actually have 10 choices for each character in your password which would give you 100,000 possibilities.
How many 3 letter passwords can be made using the letters A through Z if?There are 15,600 different 3-letter passwords, with no letters repeating, that can be made using the letters a through z. A 3-letter password, with no letters repeating, using the letters a through z, is simply a permutation of 3 letters taken from the alphabet, which has 26 letters.
How many 5 letter arrangements can be formed from the alphabet if repetition of letters is not allowed?26P5=26×25×24×23×22=7893600 different words.
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