1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Sav [38]
3 years ago
14

In a necklace, there are 2 white beads for every 7 purple beads. There is a total of 8 white beads. How many purple beads are in

the necklace?
Mathematics
1 answer:
tresset_1 [31]3 years ago
4 0

Answer:

OK! So this is a case of circular permutation. While dealing with this type of problems, we consider the circle to be placed in free space i.e it is symmetric when viewed from and point around it. So to break the symmetry we first fix one of the beads.

Here I am taking a red bead. Now we are left with 4 red and 2 blue beads.

6 beads can be placed in 6! Ways as 1st place will have 6 possibilities, 2nd place will have 5 possibilities and so on which gives

6*5*4*3*2*1 = 6!

But this time we have considered some extra cases as well because the red and blue beads are identical so which red bead has occupied a specific position will not at all matter. So we divide the total by 5! For identical red beads (the fixed red bead will also affect the position of other beads) and 2! For identical blue beads.

Finally we have 6!/(5! *2!) = 720/(120*2) = 3.

So we can have 3 different necklaces.

As the number is small, we can even enlist the possibilities…

B B R R R R R

B R B R R R R

B R R B R R R

You might be interested in
Double check my answer plssssss!!!!!!!!!!!!!!!!!!!!
emmainna [20.7K]
<span>THE ANSWER: 

</span>112 - 7 = 105
105 <span>÷ 7 = 15
</span>x = 15
7 0
3 years ago
1.1.31
miv72 [106K]

Answer:yes

  • Step-by-step explanation:well its just yes so your welcome

7 0
3 years ago
A movie theater was organizing its movie posters for an upcoming sale they found that for every 5 action movie posters they were
adoni [48]

Answer:

5

Step-by-step explanation:

5

8 0
3 years ago
QUICK If r+t = r and r−t = −s which of the following must be equal to t?
lord [1]

Answer:

Well t has to be zero, for r+t to equal r itself. so -s is equal to r, because it's r-0. Answer is C

5 0
3 years ago
What is 949 rounded to the nearest ten and hundred
myrzilka [38]
Rounded to nearest ten--- 950 Rounded to nearest hundred--- 900 A trick you can use for rounding-------- 5 or more, raise the score; 4 or less, let it rest.
3 0
3 years ago
Read 2 more answers
Other questions:
  • What is a reasonable estimate of 1/12+7/8
    15·1 answer
  • What fraction is equivalent to -5/9
    15·1 answer
  • Please help with this coin problem, include an explanation pleaasee! Thank you​
    6·2 answers
  • The point (5,4) is rotated 180° clockwise
    9·1 answer
  • A surveyor is 40m from the edge of a building. The angle of elevation from the surveyor to the top of the building is 55° . What
    8·1 answer
  • The equation of a line is y = 1.5x_2. What are it’s slope and y- intercet
    5·2 answers
  • Increased competition for power among European states and led to imperialism.
    7·2 answers
  • What is the equal value of 2⁷​
    10·1 answer
  • Samuel saved some money for a new phone, but then he spent $24 of his savings on a
    13·1 answer
  • What is the domain of this function?
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!