Palindromic Number

Find a four-digit palindromic number that is divisible by 25 and not divisible by 3.

Note: A palindromic number is a number that does not change if its digits are read in reverse order. For example, the number 5775 is a palindromic number, and the number 5778 is not a palindromic number.

Difficulty level (1 very easy - 10 very hard): 2

Number Theory -> Modular Arithmetic / Remainder Arithmetic -> Divisibility Rules -> Divisibility Rules by 3 and 9 Number Theory -> Division -> Parity (Even/Odd) Number Theory -> Modular Arithmetic / Remainder Arithmetic -> Divisibility Rules -> Divisibility Rules by 5 and 25 Combinatorics -> Case Analysis / Checking Cases -> Processes / Procedures

Sources:

Young Mathematician Olympiad, 2017-2018, Stage A, Grades 3-4 Question 5

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