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3 years ago

A relay team of 4 swimmers is to be formed from a swim team with 20 member. How many different relay teams are possible?

1 answer:

5 0

When order does not matter you use what is called n choose k formula

n!/(k!(n-k)!) where n is the number of things to choose from and k is the number of choices made, in this case:

20!/(4!(20-4)!)=4845

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Find the value of the following expression: (2^8 ⋅ 5^−5 ⋅ 19^0)^−2 ⋅ 5 to the power of negative 2 over 2 to the power of 3, whol

koban [17]

Answer:

$\large\boxed{\dfrac{5^2\cdot57}{2^{26}}=\dfrac{1425}{67108864}}$

Step-by-step explanation:

$\left(2^8\cdot5^{-5}\cdot19^0\right)^{-2}\cdot\left(\dfrac{5^{-2}}{2^3}\right)^4\cdot228\\\\\text{use}\ a^{-n}=\dfrac{1}{a^n}\ \text{and}\ a^0=1\ \text{and}\ (a^n)^m=a^{nm}\\\\=\left(2^8\cdot\dfrac{1}{5^5}\cdot1\right)^{-2}\cdot\left(\dfrac{\frac{1}{5^2}}{2^3}\right)^4\cdot228=\left(\dfrac{2^8}{5^5}\right)^{-2}\cdot\left(\dfrac{1}{2^35^2}\right)^4\cdot228$

$=\dfrac{(2^8)^{-2}}{(5^5)^{-2}}\cdot\dfrac{1^4}{(2^3)^4(5^2)^4}\cdot228=\dfrac{2^{-16}}{5^{-10}}\cdot\dfrac{1}{2^{12}5^8}\cdot228\\\\\text{use}\ a^n=\dfrac{1}{a^{-n}}\to\dfrac{1}{a^n}=a^{-n}\\\\=2^{-16}\cdot5^{10}\cdot2^{-12}\cdot5^{-8}\cdot228\\\\\text{use}\ a^n\cdot a^m=a^{n+m}\\\\=2^{-16+(-12)}\cdot5^{10+(-8)}\cdot228=2^{-28}\cdot5^2\cdot228\\\\=2^{-28}\cdot5^2\cdot4\cdot57=2^{-28}\cdot5^2\cdot2^2\cdot57=2^{-28+2}\cdot5^2\cdot57\\\\=2^{-26}\cdot5^2\cdot57=\dfrac{5^2\cdot57}{2^{26}}$

$\large\boxed{\dfrac{5^2\cdot57}{2^{26}}=\dfrac{1425}{67108864}}$

4 0

3 years ago

A sandbox in the shape of a rectangular prism is 2 feet deep and 6 feet wide. Filled to the top it can hold 72 cubic feet of san

Sedbober [7]

Answer:

height=6 ft

Step-by-step explanation:

-The volume of a rectangular prism is given by the formula:

$V=lwh$

#We make h the subject of the formula the solve for it:

$V=lwh\\\\\frac{V}{lw}=h\\\\\therefore h=\frac{V}{lw}$

#Substitute to solve for height:

$h=\frac{V}{lw}\\\\=\frac{72}{2\times 6}\\\\=6\ ft$

Hence, the prism has a height of 6 ft.

6 0

3 years ago

2. Three square rooms in Joey's house meet to form a right triangle as shown. Joey

Oxana [17]

Answer:

The amount of carpet needed in Room Z should be the same as the carpet needed in both Room X and Room Y.

Step-by-step explanatio

3 0

3 years ago

Read 2 more answers

What is the length of the hypotenuse of the triangle? A 7 cm B 3 cm

photoshop1234 [79]

Answer

The answer would be 58

Step-by-step explanation:

3 to the power of 2 is 9

7 to the power of 2 is 49

add that you get 58

3 0

3 years ago

Numbered disks are placed in a box and one disk is selected at random. If there are 6 red disks numbered 1 through 6, and 2 yell

Tatiana [17]

Answer:

$\frac{3}{4}$

Step-by-step explanation:

Total number of red disk=6

Total number of yellow disk=2

Total disk=6+2=8

Odd number=1,3,5,7=4

Odd number on red disk=1,3,5=3

Probability, $P(E)=\frac{favorable\;cases}{total\;number\;of\;cases}$

Using the formula

The probability of getting odd number disk= $\frac{4}{8}=\frac{1}{2}$

The probability of getting odd numbered red disk= $\frac{3}{8}$

The probability of selecting a red disk,given that an odd numbered disk is selected= $\frac{\frac{3}{8}}{\frac{1}{2}}=\frac{3}{8}\times 2=\frac{3}{4}$

Using conditional probability

$P(A/B)=\frac{P(A\cap B)}{P(B)}$

6 0

3 years ago