Hint: The number 121 is palindromic. Find the reverse of this number and add 8 to it.
We have been given the number 121.
Complete step-by-step answer:
When we reverse number 121, we will get 121 only. Such numbers are called Palindrome numbers.
A palindromic number is a number that remains the same when its digits are reversed.
If we take the original number and reverse it i.e. 121 and reverse it, we still get 121.
We can say more examples like 11, 131, 242 etc which when we reverse we get the same number.
For numbers like 119, 234, 122 etc is not palindrome because the reverse of 119 is equal to 911.
Reverse of 234 is 432. Similarly, the reverse of 122 is 221.
Therefore, numbers like these are not palindromes.
Therefore, reverse of 121 = 121.
Now let us add 8 to the reversed number 121 or palindrome 121 = 121 + 8 = 129.
Hence, when we reverse the number 121 and 8 to it, we get 129.
\[\therefore \]Option (a) is the correct answer.
Note: We don’t need too much theory to prove this. By seeing 121, we know that reverse will also be 121. So adding 8 to it we will get 129, whereas, options (b) and (c) are wrong.
If we were adding 9 to 121, we will get 130.
