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A sequence of no. a1,a2,a3 ..... satisfi...

A sequence of no. `a_1,a_2,a_3 `..... satisfies the relation `a_n=a_(n-1)+a_(n-2)` for `nge2`. Find `a_4` if `a_1=a_2=1`.

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Putting n=2 in the given relation
`a_3=a_1+a_2=2`
`therefore n=3 rArra_4=a_3+a_2=(2+1)=3`
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PATHFINDER-PROGRESSION AND SERIES -QUESTION BANK
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  2. Find the sum to n terms of the series whose n^th term is n(n+3).

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  3. Find the first negative term of the series 2000, 1995, 1990,1985...

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  4. If the sum of n terms of an A.P. is nP+1/2n(n-1)Q, where P and Q are c...

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  5. The sum of n terms of two arithmetic progressions are in the ratio (3...

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  6. The sum of four integar in A.P is 24 and their product is 945. Find th...

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  7. Find the sum of the series 1.n+2(n-1)+3(n-2)+.....n.1.

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  8. Find the sum of n terms of the series ab+(a-1)(b-1)+(a-2)(b-2)+.... if...

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  9. Insert 6 no. between 3 and 24 such that the resulting sequence is an ...

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  10. Between two no. whose sum is 13/6, an even no. of A.M's are inserted ....

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  11. Which term of the G.P. 2,8,32,.... upto n terms is 131072 ?

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  12. Find the least value of n for which 1+3+3^2+....+3^(n-1) gt 1000.

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  13. If p^th ,q^th and r^th terms of a G.P. be a, b, c(a,b,c>0) , prove tha...

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  14. Find the sum of first n terms and the sum of first 5 terms of the geom...

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  15. How many terms of the G.P 3,3/2,3/4 ...... are needed to give the sum ...

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  16. If a1,a2,a3(a1 gt0) are in G.P with common ratio r, then the value of...

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  17. The sum of first three terms of a G.P is 13/12 and their products is -...

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  18. Find the sum of the sequence 7,77,777,7777,......to n terms.

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  19. Find the natural no. a for which sum (k=1)^nf(a+k)=16(2^n-1) where the...

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  20. If x=1+a+a^2+a^3+......infty and y=1+b+b^2+b^3+......infty show that 1...

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