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About LinkBacksIn the infinite sequence A,,
where x is a positive integer constant. For what value of n is the ratio
ofto
equal to
?
(A) 8
(B) 7
(C) 6
(D) 5
(E) 4
source: mgmat
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Hard one
In the infinite sequence A,
where x is a positive integer constant. For what value of n is the ratio
of
(A) 8
(B) 7
(C) 6
(D) 5
(E) 4
source: mgmat
is it B ? n = 7
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In the middle of difficulty, lies opportunity - Albert Einstein
I wud go for B too... whats the answer..!
I get answer of 7, or B, too. How would you approach this problem in general other than plugging in the answers after expanding the denominator?
any more thoughts on this one
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The method I followed was to reduce the Q to (x^6/ x ) * ( Y/Y)
the eqn An= (x ^ n -1)(1+ x + x^2 + x^3 +.... ) ----------------------------(1)
and the eqn x(1+x(1+x(1+x...))))
which i call Z can be reduced to x( 1+x+x^2+x^3 ..) --------(2)
from (1) and (2) we get An / Z = x^(n-1) / x
therefore for getting answer x^5 (n-1) = 6
therefore n=7
Ans: B
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Its B.
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b for me too
Sargataur, is this the type of question one would encounter on the GMAT?Originally Posted by Sargataur
[QUOTE=Stormgal]In the infinite sequence A,
where x is a positive integer constant. For what value of n is the ratio
of
(A) 8
(B) 7
(C) 6
(D) 5
(E) 4
the answer is B
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