There is a sequence ni such, in which i is a positive integer, ni+1=2ni.
If n1=1, n2=2, n3=4, n4=8, what is the scope including n11?  Pick one
A) 10~100	B) 1,000~10,000	C) 10,000~100,000	D) 100,000~1,000,000	E) 1,000,000~
-&gt; ni=2^(i-1) -&gt; 2^10=1,024&gt;1,000=10^3 -&gt; n11=2^10=(2^10)&gt;(10^3)=10^3   Thus, the answer is 1,000~10,000.
<result>B</result>
There is a sequence ni such, in which i is a positive integer, ni+1=2ni.
If n1=1, n2=2, n3=4, n4=8, what is the scope including n11?