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Ivahew [28]
3 years ago
11

Find the sum of the given arithmetic series. 14 + 28 + 42 + 56 + ... + 280

Mathematics
1 answer:
cricket20 [7]3 years ago
6 0

14 + 28 + 42 + 56 + … 280

= 14 (1 + 2 + 3 + 4 + … + 20)

= 14 × 20 × 21 / 2

= 2940

where we use the well-known identity,

\displaystyle \sum_{i=1}^ni = 1 + 2 + 3 + \cdots + n = \dfrac{n(n+1)}2

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A certain town never has two sunny days in a row. Each day is classified as being either sunny, cloudy (but dry), or rainy. If i
11111nata11111 [884]

Answer:

the proportion of days that are Sunny is 0.2

Step-by-step explanation:

Given the data in the question;

Using markov chain;

3 states; Sunny(1), Cloudy(2) and Rainy(3)

Now, based on given conditions, the transition matrix can be obtained in the following way;

\left[\begin{array}{ccc}0&0.5&0.5\\0.25&0.5&0.25\\0.25&0.25&0.5\end{array}\right]

so let the proportion of sunny, cloudy and rainy days be S, C and R respectively.

such that, from column 1

S = 0.25C + 0.25R   -------------let this be equation 1

from column 2

0.5C = 0.5S + 0.25R

divided through by 0.5

C = S + 0.5R ---------------------- let this be equation 2

now putting equation 2 into equation;

S = 0.25(S + 0.5R) + 0.25R

S = 0.25S + 0.125R + 0.25R

S - 0.25S = 0.375R

0.75S = 0.375R

S = 0.375R / 0.75

S = 0.5R

Therefore,

from equation 2; C = S + 0.5R

input S = 0.5R

C = 0.5R + 0.5R

C = R

Now, we know that, the sum of the three proportion should be equal to one;

so

S + C + R = 1

since C = R and S = 0.5R

we substitute

0.5R + R + R = 1

2.5R = 1

R = 1/2.5

R = 0.4

Hence, the proportion of days that are Rainy is 0.4

C = R

C = 0.4

Hence, the proportion of days that are Cloudy is 0.4

S = 0.5R

S = 0.5(0.4)

S = 0.2

Hence, the proportion of days that are Sunny is 0.2

8 0
3 years ago
PLEASE HELP ASAP 35 PTS + BRAINLIEST TO RIGHT/BEST ANSWER
Semenov [28]

Answer:

(5,2,2)

Step-by-step explanation:

-3x+4y+2z = -3

2x-4y-z=0

y = 3x-13


Multiply the second equation by 2

2*(2x-4y-z)=0*2

4x -8y -2z =0

Add this to the first equation to eliminate z

-3x+4y+2z = -3

4x -8y -2z =0

-------------------------

x -4y = -3

Take the third equation and substitute it in for y

x - 4(3x-13) = -3

Distribute the 4

x - 12x +52 = -3

Combine like terms

-11x +52 = -3

Subtract 52 from each side

-11x +52-52 = -3-52

-11x = -55

Divide by -11

-11x/-11 = -55/-11

x=5

Now we can solve for y

y =3x-13

y =3*5 -13

y = 15-13

y=2

Now we need to find z

2x-4y-z=0

2(5) -4(2) -z=0

10-8 -z=0

2-z=0

Add z to each side

2-z+z= 0+z

2=z

x=5, y=2, z=2

(5,2,2)

3 0
2 years ago
How many hundreds flats are equal to 400 tens rods
vitfil [10]
40 hundreds flats. 400 tens = 4,000. 40 hundreds also equals 4,000.
4 0
3 years ago
Read 2 more answers
Boy Scouts Popcorn Sales
Karolina [17]

Answer:

60

Step-by-step explanation:

5 plus 4 is nine.

I based everything on how much times more it was at first, and did that times 9 for every name.

I added up how much more boxes they got in total and got 60.

3 0
2 years ago
A rectangle is plotted on the coordinate grid. It has vertices at (-3, 5), (4, 5), (4, -1), and (-3, -1). Which choices below ar
zhannawk [14.2K]

A rectangle is plotted on the coordinate grid. It has vertices at (-3, 5), (4, 5), (4, -1), and (-3, -1). Which choices below are the dimensions of the rectangle?

Answer

(-3,5)

3 0
2 years ago
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