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Ymorist [56]
4 years ago
10

For a group of 100 people, compute(a) the expected number of days of the year that are birthdays of exactly 3 people.(b) the exp

ected number of distinct birthdays.
Mathematics
1 answer:
Scilla [17]4 years ago
4 0

Answer:

Step-by-step explanation:

Leaving leap years, a year contains 365 days.

For a group of 100 people, each person is independent of the other and probability of any day being his birthday has a chance of

\frac{1}{365}

a) Probability that  exactly 3 people have same birthday = \frac{1}{365^3}

Each day is independent of the other

And hence no of days having exactly 3 persons birthday out of 100 persons is binomial with n = 365 and p = \frac{1}{365^3}

Expected value of days = np = \frac{1}{365^2}

b) Distinct birthdays is binomail with p =1/365 and n = 365

Hence

expected value = np =1

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Gnesinka [82]

Answer:

x<6/5, x>14/5

Step-by-step explanation:

Steps

$5\left|x-2\right|+4>8$

$\mathrm{Subtract\:}4\mathrm{\:from\:both\:sides}$

$5\left|x-2\right|+4-4>8-4$

$\mathrm{Simplify}$

$5\left|x-2\right|>4$

$\mathrm{Divide\:both\:sides\:by\:}5$

$\frac{5\left|x-2\right|}{5}>\frac{4}{5}$

$\mathrm{Simplify}$

$\left|x-2\right|>\frac{4}{5}$

$\mathrm{Apply\:absolute\:rule}:\quad\mathrm{If}\:|u|\:>\:a,\:a>0\:\mathrm{then}\:u\:<\:-a\:\quad\mathrm{or}\quad\:u\:>\:a$

$x-2<-\frac{4}{5}\quad\mathrm{or}\quad\:x-2>\frac{4}{5}$

Show Steps

$x-2<-\frac{4}{5}\quad:\quad x<\frac{6}{5}$

Show Steps

$x-2>\frac{4}{5}\quad:\quad x>\frac{14}{5}$

$\mathrm{Combine\:the\:intervals}$

$x<\frac{6}{5}\quad\mathrm{or}\quad\:x>\frac{14}{5}$

5 0
3 years ago
Divide 2,756 into 1,375,244​
alexgriva [62]

Answer:

499

Step-by-step explanation:

you take 1,375,244/2,756=499

3 0
3 years ago
Read 2 more answers
A bag of marbles contains 4 red marbles, 5 yellow marbles, 2 green marbles, and 7 blue marbles. You draw one marble from the bag
klio [65]
This is an example of probability.
4 0
3 years ago
Laurent invested some money in a bank account.
zavuch27 [327]

Answer:

1.04

Step-by-step explanation:

"Complete the following sentence about the yearly rate of change in the amount of money in the account.  Round your answer to two decimal places.

Every year, the amount of money in the account increases by a factor of _."

Mdecade(t) = 4900 (1.5)^t, where t is in decades.

One year is 0.1 decades, so M increases by a factor of:

1.5^0.1 = 1.04

4 0
3 years ago
HOW DO I FIND QR<br><br> PLEASE HELP
Paul [167]

Solution: For finding QR we need to apply Pythagoras Theorem

What is Pythagoras Theorem ?

ans : Pythagoras Theorem is the sum of square of two sides which is equal to the third side or the hypotenuse. This formula is valid oy incase of Right-Angled Traingle because one of three angles here is 90°

According to this law let's apply it in the diagram shown here.

  • (Hypotenuse)² = (Adjacent)² + (Opposite)²

  • (PR)² = (QR)² + (PQ)²

  • (5x - 2)² = (QR)² + (3x - 1)²

  • (QR)² = (5x - 2)² - (3x - 1)²

After factorising both of them we get

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  • (QR)² = 25x² - 20x + 4 - 9x² + 6x - 1

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  • QR = √(16x² - 14x + 3)

So, QR is √(16x² - 14x + 3)

8 0
3 years ago
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