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Reptile [31]
3 years ago
14

Find the sum of ( 1- 1/n) + (1 - 2/n) + ( 1 - 3/n)...upto n terms

Mathematics
1 answer:
Lapatulllka [165]3 years ago
5 0

Answer:

(n-1) / 2

Step-by-step explanation:

We have that the sum has the form of:

Sn = n / 2 [2 * a + (n-1) * d]

we compute the terms of a and d

a = 1 - 1 / n

a = (n - 1) / n

, that is, the first term, in the case d is the subtraction between the second and the first term, thus:

d = 1 - 2 / n - (1 - 1 / n)

d = 1 - 2 / n - 1 + 1 / n

d = - 1 / n

now if replacing these values:

Sn = n / 2 * [2 * (n - 1) / n + (n-1) * (- 1 / n)

Sn = n / 2 * [2 * (n-1) - (n-1)] / n

Sn = 1/2 * (n-1)

Therefore, the value of that sum is (n-1) / 2

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Answer:

3.7 hours

Step-by-step explanation:

Pat could do the job alone in 8 hours.

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Output = Rate * time

Let the rate at which pat does the work = Rp

Let the rate at which Patti does the work = Rt

Let X be the total output

Rp * 8 = X

Rp = X/8

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Rt = X/7

If both pat and Patti pick apples, we have

(Rp+Rt)T = X

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T = 56/15

T = 3.7 hours

8 0
3 years ago
Is 2 3/4 <, >, or = to 2.75%
lesya692 [45]
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</span>2 3/4  = 2.75%
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3 years ago
Ms. Willer wanted to donate 27 cans of food to each of 8 food banks each of food to each of 8 food banks each of the 23 students
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IceJOKER [234]
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10 points
Y_Kistochka [10]

Answer:

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Step-by-step explanation:

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