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If the sum of n terms of an A.P. is 3n^2...

If the sum of `n` terms of an A.P. is `3n^2+5n` and its mth term is 164, find the value of `mdot`

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The correct Answer is:
m=27
` T_(n) = (S_(n) -S_(n-1)_=(3n^(2)+5n) -(3n^(2)-n-2) = (6n +2)`
T_(m)=164 Rightarrow +2 =164 Rightarrow 6m = 162 Rightarrow m=27`
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RS AGGARWAL-ARITHMETIC PROGRESSION-Exercise 11B
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  2. Find the value of x such that 25+22+19+16 +….+ x=112

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  3. Find the rth term of an AP, the sum of whose first n terms is (3n^(2) ...

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  4. find the sum of n terms of an AP whose rth term is ( 5r+1)

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  9. The sums of n terms of two arithmetic progressions are in the ratio (7...

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  10. IF the ratio between the sums of n terms of two arithmetic progression...

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  11. Find the sum of all odd integers from 1 to 201.

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  12. Find the sum of all even integers between 101 and 199.

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  13. Find the sum of all integers between 101 and 500, which are divisible...

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  14. Find the sum of all integers between 100 and 600, each of which when ...

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  15. The sum of first 7 terms of an A.P. is 10 and that of next 7 terms is ...

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  16. If the sum of n terms of an A.P. is 3n^2+5n and its mth term is 164, f...

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  17. Find the sum of all natural numbers from 1 and 100 which are divisble ...

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  18. If the sum of n terms of an A.P. in n P" "+1/2n(n-1)Q , where P and...

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  19. If S(m)=m^(2) p and S(n)=n^(2)p, where m ne n in an AP then prove tha...

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