Correct option is (D) 111
First number between 1 & 1000 which is divisible by 9 is 9
& last number between 1 & 1000 which is divisible by 9 is 999.
i.e., \(a_1=a=9\;\&\;a_n=999,d=9\)
\(a_n=a+(n-1)d\)
\(\Rightarrow999=9+(n-1)d\)
\(\Rightarrow9(n-1)=999-9=990\)
\(\Rightarrow n-1=\frac{990}9=110\)
\(\Rightarrow n=110+1=111\)
Hence, there are total 111 numbers which are divisible by 9 in between 1 & 1000.
