Question 135
A natural number is called a palindrome if it equals the number obtained by reading the digits of its base-ten representation from right to left (for example, 68386 and 44 are palindromes, 220 is not). We know that the natural number $x$ and the number $x+312$ are both palindromes; $x$ has four digits, while $x+312$ has five. What is the sum of the digits of $x$ ?
(A) 30
(B) 31
(C) 32
(D) 33
(E) 34
(A) 30
(B) 31
(C) 32
(D) 33
(E) 34