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Examples

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Question

The income of a person is in the first year and he receives an increase of to his income per year for the next 19 years. Find the total amount, he received in 20 years.

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Solution

Here, we have an and . Using the sum formula, we get

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Question

Insert 6 numbers between 3 and 24 such that the resulting sequence is an A.P.

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Solution

Let and A6 be six numbers between 3 and 24 such that 3, are in A.P. Here,

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Question

Find the sum to n terms of the series:

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Solution

On Subtraction,

k varies from 1 to n

=

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Question

If A.M. and G.M. of two positive numbers a and b are 10 and 8, respectively, find the numbers.

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Solution

a +b = 20

The numbers and b are respectively.