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Sav [38]
2 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]2 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

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Answer:

I belive it would be c

Step-by-step explanation:

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7 0
3 years ago
A random sample of 60 mathematics majors spent an average of $200.00 for textbooks for a term, with a standard deviation of $22.
tangare [24]

Answer:

20 +/- $6.74

= ( $13.26, $26.74)

The 90% confidence interval for the difference in average amounts spent on textbooks (math majors - English majors) is ( $13.26, $26.74)

Step-by-step explanation:

Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.

The confidence interval of a statistical data can be written as.

x1-x2 +/- margin of error

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Given that;

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Standard deviation r1 = $22.50

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z(at 90% confidence) = 1.645

Substituting the values we have;

$200-$180 +/-1.645(√(22.5^2/60 +18.3^2/40)

$20 +/- 6.744449847374

$20 +/- $6.74

= ( $13.26, $26.74)

The 90% confidence interval for the difference in average amounts spent on textbooks (math majors - English majors) is ( $13.26, $26.74)

3 0
3 years ago
Some1 hurry up and help me plzzz!!!
sladkih [1.3K]
The answer is D hope this helps
4 0
2 years ago
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Hi,


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Hope this helps.
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Maria measure the height of her Seedlings. There were 3/4 inches 7/8 inches 1 1/2 inches 3/4 inches five8 inches 3/4 inches 78 i
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Answer:

IDK i am trying to solve the same problem. I am sorry

Step-by-step explanation:

7 0
3 years ago
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