Question

A number of decimal system when represented in binary system then its first and last digits are same and the rest digits are also of another kind. Further this number appears to be palindrome of numerals. The number is:

• A. 57
• B. 19
• C. 8
• D. 9

Answer 1

The correct option is D 9

Going through option:
Let us assume option (c), then

Since $(1000{)}_2$ does not satisfy the given condition hence presumed option is wrong.
Now, consider option (d).

Thus $(9{)}_{10}$ = (1001), which satisties all the given condition hence correct option.