Tutors Answer Your Questions about Permutations (FREE)
Question 599207: An internet site requires a 6 character password made up of 2 digits followed by 4 letters where uppercase letters are not the same as lowercase letters. Without repetition of letters or numbers, how many different passwords can be created?
Click here to see answer by math-vortex(472)  |
Question 600069: A clerk had only 10 vacant rooms left in one hotel. There were 11 men who went into the hotel at the same time, each wanting a separate room. The clerk, settling the argument said, "I'll tell you what I'll do. I will put two men in Room 1 with the understanding that I will come back and get one of them a few minutes later." The men agreed to this. The clerk continued, "I will put the rest of you men as follows:
the 3rd man in Room 2
the 4th man in Room 3
the 5th man in Room 4
the 6th man in Room 5
the 7th man in Room 6
the 8th man in Room 7
the 9th man in Room 8 and
the 10th man in Room 9
Then the clerk went back to get the extra man he had left in Room 1, and put him in Room 10. Everybody is happy. What is the fallacy of this plan?
Click here to see answer by htmentor(789)  |
Question 601739: Whats the formula and answer for this problem:
A women is going out for the evening.She will put on one of 6 dresses, one pair out of 8 pairs of shoes, and go to one of 7 restaurants. In how many days can this be done?
Thank You in advance!
Click here to see answer by josmiceli(9690)  |
Question 602332: Help please on Permutations.
Problem:
how many ways can 15 students be separated into two groups of 8 and 7?
Attempt:
Since they will be separated into 2 groups, i tried using 15!/7! since the rest (those seven left) will be on the other group, but it does not show the combinations for the other group. And so i am wrong. :/
Click here to see answer by scott8148(6628)  |
Question 604095: The door code to get into a top secret laboratory is 6 digits. the first 3 digits of the code are all odd and the last 3 digits are all even. Digits can be used more than once. How many possible codes are there to gain access to this laboratory?
This is a Permutations and Combinations question.
Click here to see answer by jim_thompson5910(28595) |
Question 604911: Jace's collection of sports cards includes ten baseball, seven basketball, and nine football cards. He wants to give away two cards from different sports to his friend for a birthday present. How many ways can he choose the two cards?
I have tried 26P2 and 26C2 but I am not sure if any of these are right. I have also tried 26!/10!7!9!
I am not sure if I am working this problem out right. Please help my understand how this problem is worked out.
Thank you so much for your help!
Click here to see answer by jim_thompson5910(28595) |
Question 604708: There are 10 first-tier national rugby union teams.
(a) How many different two-team pairings are possible among those 10 teams.
I guess, the answer to this will be C(10,2) = 45 ways
I am stuck in the following
(b) how many different ways are there to select a 1st, 2nd and 3rd ranked teams from these teams
(c) Suppose 4 teams are going to gather in Sydney, the other 6 teams in Melbourne. How many ways it can be done?
Thanks
Click here to see answer by scott8148(6628)  |
Question 605243: 6 boys and 5 girls are to be seated around a table. Find the number of ways that this can be done in each of the following cases.
a. there are no restrictions
b. no 2 girls are adjacent
c. all girls form a single block
d. a particular girl G is adjacent to two particular B1 and B2
Click here to see answer by Edwin McCravy(8909)  |
Question 607029: So there are three seats, each one can either be filled by a boy or a girl. How many different combinations are there with repetition?
I know that there are 4:
BBB
BBG
BGG
GGG
However, I don't know the equation to find this... Could you help? Much obliged!
Click here to see answer by jim_thompson5910(28595) |
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Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780
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