In the sequence of positive number x1, x2, x3,.......what is the value of xi
1 x1 = xi -1 /2 for all integers i > 1
2 x5 = x4/x4+1
1 x1 = xi -1 /2 for all integers i > 1
2 x5 = x4/x4+1
Neither statement alone is sufficient.In the sequence of positive numbers X�, X₂, X₃....what is the value of X�?
(1) Xⅈ = (Xⅈ-�)/2 for all integers ͥͥⅈ > 1
(2) Xâ‚… = Xâ‚„/(Xâ‚„+1)
Combined:
In statement 2, Xâ‚… = Xâ‚„/(Xâ‚„+1).
In statement 1, when â…ˆ=5, Xâ‚… = Xâ‚„/2.
In each equation, the righthand side is equal to Xâ‚….
Equating the righthand sides, we get:
Xâ‚„/(Xâ‚„+1) = Xâ‚„/2
Xâ‚„+1 = 2
Xâ‚„ = 1.
Since statement 1 indicates that each term is 1/2 the preceding term, we get:
X₃ = 2
Xâ‚‚ = 4
X� = 8.
SUFFICIENT.
The correct answer is C.
