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If the sum of a certain number of terms of the A.P. 25, 22, 19.... is 116. Find the last term.

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Here, first term, `a = 25`
Common difference, `d = -3`
Sum,`S_n = 116`
So,
`n/2(2a+(n-1)d ) = 116`
`=>n/2(2**25+(n-1)(-3) ) = 116`
`=>n(50+3-3n) = 232`
`=>3n^2-53n +232 = 0`
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NCERT ENGLISH-SEQUENCES AND SERIES-EXERCISE 9.2
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  2. Insert five numbers between 8 and 26 such that the resulting sequence...

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  3. A mail starts repaying a loan as first instalment of Rs. 100. If he i...

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  4. The difference between any two consecutive interior angles of a polyg...

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  5. Between 1 and 31, m numbers have been inserted in such a way that the...

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  6. If the sum of first p terms of an A.P. is equal to the sum of the fir...

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  7. If the sum of n terms of an A.P. is 3n^2+5and its m^(t h)term is 164,...

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  8. The ratio of the sum of m and n terms of an A.P. is m^(2) :n^(2). Show...

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  9. If (a^n+b^n)/(a^(n-1)+b^(n-1))is the A.M. between a and b, then find t...

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  10. If the sum of n terms of an A.P. is (p n+q n^2) , where p and q are...

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  11. The sums of n terms of two arithmetic progressions are in the ratio 5...

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  12. If the sum of a certain number of terms of the A.P. 25, 22, 19.... is...

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  13. Find the sum to n terms of the A.P., whose k^(t h)term is 5k + 1.

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  14. How many terms of the A.P. 6, -(11)/2,-5,dotdotdotare needed to give...

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  15. In an A,P if the pth term is (1)/(q) and q^(th) terms is (1)/(p). Prov...

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  16. Find the sum of all natural numbers lying between 100 and 1000, which...

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  17. In an A.P., the first term is 2 and the sum of the first five terms i...

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  18. Find the sum of odd integers from 1 to 2001.

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