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knight247
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If x1,x2,x3....xn is a sequence of positive integers such that xn+2=xn*xn+1. What is the least possible value of x1 if |x3-x2|=10?
(A)3
(B)5
(C)4
(D)1
(E)2
The OA says A But I'm getting a value of 2
Here is how i did it
|x3-x2|=10
|x2*x1-x2|=10
|x2||x1-1|=10
Since both x2 and x1 are positive
the options are
x2=5 and x1-1=2 so x1=3
or
x2=2 and x1-1=5 so x1=6
Hence, x1=3 as it is the minimum value
But, can't we also consider another option as follows?
x2=10 and x1-1=1 so x1=2
or
x2=1 and x1-1=10 so x1=11
Making x1=2 and hence making the answer E. Opinions?
(A)3
(B)5
(C)4
(D)1
(E)2
The OA says A But I'm getting a value of 2
Here is how i did it
|x3-x2|=10
|x2*x1-x2|=10
|x2||x1-1|=10
Since both x2 and x1 are positive
the options are
x2=5 and x1-1=2 so x1=3
or
x2=2 and x1-1=5 so x1=6
Hence, x1=3 as it is the minimum value
But, can't we also consider another option as follows?
x2=10 and x1-1=1 so x1=2
or
x2=1 and x1-1=10 so x1=11
Making x1=2 and hence making the answer E. Opinions?
