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The sum of the first four terms of an A....

The sum of the first four terms of an A.P. is 56. The sum of the last four terms is 112. If its first term is 11, then find the number of terms.

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The correct Answer is:
` :. 8n = 88` or `n = 11`
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NEW JOYTHI PUBLICATION-SEQUENCES AND SERIES -QUESTIONS FROM COMPETITIVE EXAMS
  1. The sum of the first four terms of an A.P. is 56. The sum of the last ...

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  2. The sum to n terms of the series 1/2 + 3/4 + 7/8 + 15/16 + ....... is

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  3. 0.2 + 0.22 + 0.222 + …….. to n terms =

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  4. If (a^(n + 1) + b^(n + 1))/(a^(n) + b^(n)) is the arithmetic mean betw...

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  5. If (i)^(2) = -1, (i)^(2) + (i)^(4) + (i)^(6) + ...... to (2n + 1) term...

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  6. If S(n) denotes the sum of n terms of an A.P., S(n +3) - 3S(n + 2) + 3...

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  7. The HM of 2 numbers is 4. Their AM is A and GM is G. If G satisfies 2...

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  8. The angle of triangle are in 30^(@). The greatest angle in radians is

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  9. How many terms of the geometric series 1 + 4 + 16 + 64 + ……… will make...

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  10. Find the value of n so that (a^(n+1)+b^(n+1))/(a^(n)+b^n) may be the ...

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  11. The sum of the series 1 + 2.2 + 3.2^(2) + 4.2^(3) + 5.2^(4) + ……… + 1...

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  12. If A, G, H denote respectively the AM, GM and HM between two unequal p...

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  13. Let a, b, c be district real numbers. If a, b, c are in G.P and a + b ...

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  14. The numbers of terms of the A.P 3, 7, 11, 15, …… to be taken so that t...

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  15. If the progression 3, 10, 17, …… and 63, 65, 67, …… are such that thei...

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  16. Which term of the geometric sequence 5,2,4/5 , 8/(25) … is (128)/(15...

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  17. If a, b and c are respectively the p^(th),q^(th)and r^(th) terms of an...

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  18. The sum of infinite terms of the geometric progression (sqrt(2) + 1)/(...

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  19. The two geometric means between the numbers 1 and 64 are

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  20. If 1 + (1 + 2)/2 + (1 + 2 + 3)/3 + ...... to n terms is s, then s is e...

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  21. If a, b, and c are in A.P., then which one of thew following is not tr...

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