Questions on Algebra: Combinatorics and Permutations answered by real tutors!

Tutors Answer Your Questions about Permutations (FREE)

Question 984433: In a suitable font, the letters A, H, I, M, O, T, U, V, W, X, Y are all mirror images of themselves. A string made from these letters will be a mirror image of itself if it reads the same backward as forward: for example, MOM, YUMMUY, MOTHTOM. If a four-letter string in these letters is chosen at random, what is the probability that this string is a mirror image of itself? (Round your answer to four decimal places.)

Click here to see answer by solver91311(24713)

Question 984390: The following problem refers to strings in A, B, ..., Z.
How many three-letter strings are there that begin with L ?

Click here to see answer by macston(5194)

Question 984431: Bill has eight one-piece jump suits, three pairs of work pants, and six work shirts. He either wears a jump suit, or pants and a shirt to work. How many different possible outfits does he have?
Click here to see answer by macston(5194)

Question 985012: If there are 24 contestants in a pageant, in how many different ways can they place 1st, 2nd, and 3rd

Click here to see answer by macston(5194)

Question 985051: 8 books are to be arranged in a shelf. There are 3 different Science books, 2 different Mathematics books and 3 different History books. How many different arrangements can be done if:
a.) all the books of the same subject must stand together?
b.) the books can stand irrespective of the subject?

Click here to see answer by macston(5194)

Question 985039: If you consider the numbers 1,2,3,4, and 5, how many three digit numbers can be formed if:
A. Repetition is not allowed and such that they are all:
1. Greater than 200
2. Ending in 5
3. odd numbers
B. Repetition is allowed such that they are all:
1. even numbers
2. Less than 500
3. having 1 or 5 in their hundreds place
Click here to see answer by macston(5194)

Question 985113: From 6 English teachers and 5 Mathematics teachers, committees of 5 teachers will be organized. How many ways can the committees be organized such that in every committee:
a.) 3 are English teachers and 2 are Mathematics teachers?
b.) Any of the teachers can be included?
c.) All are Mathematics teachers?

My soln:
a.) 6C3*5C2
b.) 11C5
c.) 5C5
Is it correct ? Thanks!
Click here to see answer by Edwin McCravy(20054)

Question 985032: Jane is taking a 10 questions multiple choice but he has not studied. Each question has 4 possible responses only one of which is correct the probability of getting each question correct is 0.25. Find the probability of getting the result below if she answers all questions randomly
A) exactly 6 questions correct
B) 4 or fewer questions correct
C) 8 or more questions correct
Click here to see answer by reviewermath(1029)

Question 985313: How many words can be formed by using all the letters of the word SCHOOL so that vowels never come together?

Click here to see answer by Edwin McCravy(20054)

Question 985300: I wish you (be) the chairman of the association
Correct tense
Click here to see answer by macston(5194)

Question 985467: The shipment of 15 washing machines contains 3 diffective pieces.in how many ways can a firm selling.washing machines purchase 5 machines and receive and at least 2 diffective pieces

Click here to see answer by Edwin McCravy(20054)

Question 986102: A(2;3),b(-2;-1) and c(-3;-2).show that these points are collinear
Click here to see answer by Timnewman(323)

Question 986234: Write the row of Pascal's Triangle whose first two entries are 1 and 7.
(Enter the entries of the indicated row separated by semicolons.)
Thank you kindly.
Click here to see answer by Alan3354(69443)

Question 986228: How can we obtain an even no. By adding 3 odd no. We could even repeat the no.
Click here to see answer by Alan3354(69443)

Question 986317: How many solutions (using only nonnegative integers) are there to the following equation?
x1 + x2 + x3 + x4 + x5 = 31
Click here to see answer by stanbon(75887)

Question 986422: A couple has 7 children. If b = boy and g = girl, how many 2-letter string combinations of boys and girls in this family will produce every possible sequence of the number of girls and the number of boys? Thank you so much for your help. IT student in Long Beach, California.
Click here to see answer by macston(5194)

Question 987122: 7P4
Click here to see answer by EdenWolf(517)

Question 987214: A board of trustees is made up of 10 people. The board is choosing a chairperson, a secretary and a publicist. If they have already decided upon a chairperson, in how many ways can they choose a secretary and a publicist?
Thanks, please show the work too . Thanks!! :)
Click here to see answer by stanbon(75887)

Question 987248: Help please, thank you.
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?
Show all work please, thanks! :)
Click here to see answer by macston(5194)

Question 987285: In how many ways can a 3 digit number be formed using the numbers 0-9, if each digit is used only one time?
help please
Thank you!
show all work please :)
Click here to see answer by MathTherapy(10552)

Question 987413: A 3-digit number will be formed using the numbers 2, 3, 4, 5, and 7. How many are less than 500 if the digits must be distinct?
Click here to see answer by macston(5194)

Question 987291: help please ,
Holly wants to choose 5 different decorative tiles out of 8. If she plans to place the 5 tiles in a row, end to end, in how many different ways can she arrange them, from left to right?
show work please thanks
Click here to see answer by macston(5194)

Question 987672: In how many ways can 8 persons be arranged together without 1st and 2nd persons coming together?
Click here to see answer by josmiceli(19441)

Question 987722: How many different groups can be selected for playing tennis out of 4 ladies and 3 gentlemen,there being one lady and one gentlemen on each side

Click here to see answer by Edwin McCravy(20054)

Question 987901: a lock has a 3-number combination in which the first number is seven less than the second number and eleven more than the third. if the sum of the three numbers is 53, what is the combination?
Click here to see answer by solver91311(24713)

Question 988258: at a school event, adults are seated in groups of exactly 6 and children are seated in groups of exactly 20. ifthere are same number of adults as children, what is the minimum number of adults attending.
Click here to see answer by vleith(2983)

Question 988226: write down the binomial expansion of (1+x)^4 and use the result to evaluate(5/4)^4, correct your answer to three decimal places
Click here to see answer by Fombitz(32388)

Question 988367: Five men and three women applied for 2 scholarships. What is the probability that the winners will be a man and a woman?
how do i solve this?
Click here to see answer by rfer(16322)

Question 988588: [ ] + [ ] + [ ] = 30
please solve this using
1,3,5,7,9,11,13,15 you can also rpeat these number
Click here to see answer by Fombitz(32388)

Question 988851: In how many ways could 13 people be divided into five groups containing, respectively, 3, 1, 4, 3, and 2 people?
Click here to see answer by Shai(25)

Question 988923: A bowl contains 9 red balls and 9 blue balls. A woman's selects 4 balls at random from the bowl. How many different selections are possible if at least 3 balls must be blue ?
Click here to see answer by Shai(25)

Question 988244: Prizes are to be awarded to four different members of a group of 8 people.Find the number of ways in which the prizes can be awarded if there are 2 first prizes and 2 second prizes?
Click here to see answer by Shai(25)

Question 984135: The legislature of Puerto Rico consists of a 27-member Senate and a 51-member House of Representatives.
How many ways are there to choose a group of six members from the Puerto Rican legislature?

Click here to see answer by Shai(25)

Question 989393: can you help me solve this please
A resort has 9 empty rooms and 7 travelers who want rooms. In how many ways can the manager assign a room to each traveler given that no two travelers can share a room?
I tried 9!/7!, I tried just 9! and just 7!, and I tried just doing 9 times 7 but everything comes back incorrect.
Click here to see answer by solver91311(24713)

Question 989699: If C(n,3)=C(n,4),then the value of n?????please help me to solve this problem.
Click here to see answer by macston(5194)

Question 989990: How many times can 1,4,5,8 be arranged?
Click here to see answer by ikleyn(52780)

Question 990311: What is the solution of log3x + 4125 = 3?
Click here to see answer by Alan3354(69443)

Question 148291: How many ways can a baseball coach choose the first, second and third batters in the lineup of a team of 15 players.
Click here to see answer by alnavy70(1)

Question 990448: -3=a-10\3
Click here to see answer by Alan3354(69443)

Question 990562: The number of ways in which the number 27720 can be split into the product of two factors that are coprimes is
Click here to see answer by ikleyn(52780)

Question 990789: how many different product of 3 digits can be formed from the digits 2,5 and 7 without repetition ?
Click here to see answer by Edwin McCravy(20054)

Question 990558: The number of ways in which the number 27720 can be split into two factors which are coprimes is
Click here to see answer by Edwin McCravy(20054)

Question 990812: How many numbersbetween 1000&10000 can be formed with the digits 1,3,5,7,9 each digit used only once in each number?
Click here to see answer by Edwin McCravy(20054)

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, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400, 5401..5445, 5446..5490, 5491..5535, 5536..5580, 5581..5625, 5626..5670, 5671..5715, 5716..5760, 5761..5805, 5806..5850, 5851..5895, 5896..5940, 5941..5985, 5986..6030, 6031..6075, 6076..6120, 6121..6165, 6166..6210, 6211..6255, 6256..6300, 6301..6345, 6346..6390, 6391..6435, 6436..6480, 6481..6525, 6526..6570, 6571..6615, 6616..6660, 6661..6705, 6706..6750, 6751..6795, 6796..6840, 6841..6885, 6886..6930, 6931..6975, 6976..7020, 7021..7065, 7066..7110, 7111..7155, 7156..7200, 7201..7245, 7246..7290, 7291..7335, 7336..7380, 7381..7425, 7426..7470, 7471..7515, 7516..7560, 7561..7605, 7606..7650, 7651..7695, 7696..7740, 7741..7785, 7786..7830, 7831..7875, 7876..7920, 7921..7965, 7966..8010, 8011..8055, 8056..8100, 8101..8145, 8146..8190, 8191..8235, 8236..8280, 8281..8325, 8326..8370, 8371..8415, 8416..8460, 8461..8505, 8506..8550, 8551..8595, 8596..8640, 8641..8685, 8686..8730, 8731..8775, 8776..8820, 8821..8865, 8866..8910, 8911..8955, 8956..9000, 9001..9045, 9046..9090, 9091..9135, 9136..9180, 9181..9225, 9226..9270, 9271..9315, 9316..9360, 9361..9405, 9406..9450, 9451..9495, 9496..9540, 9541..9585, 9586..9630, 9631..9675, 9676..9720, 9721..9765, 9766..9810, 9811..9855, 9856..9900, 9901..9945, 9946..9990, 9991..10035