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In an A.P., the first term is 2 and the ...

In an A.P., the first term is 2 and the sum of the first five terms is one-fourth of the next five terms. Show that `20^("th")` term is –112.

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NCERT BANGLISH-SEQUENCES AND SERIES-EXERCISE 9.2
  1. Find the sum of odd integers from 1 to 2001.

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

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

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  4. How many terms of the A.P. – 6, , - (11)/2 , -5 ......... are needed t...

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  5. In an A.P. if p^(th) term is 1/q and q^(th) term is 1/p , prove that t...

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  6. If the sum of a certain number of terms of the A.P. 25, 22, 19, … is 1...

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  7. Find the sum to n terms of the A.P., whose k^("th") term is 5k + 1.

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

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

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  10. If the sum of first p terms of an A.P. is equal to the sum of the firs...

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  11. Sum of the first p, q and r terms of an A.P. are a, b and c, respectiv...

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  12. The ratio of the sums of m and n terms of an A.P. is m^2 : n^2. Show ...

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  13. If the sum of n terms of an A.P. is 3n^2 + 5n and its m^("th") term ...

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  14. Insert five numbers between 8 and 26 such that the resulting sequence ...

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

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

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  17. A man starts repaying a loan as first instalment of Rs. 100. If he inc...

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  18. The difference between any two consecutive interior angles of a polygo...

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