There are 3598 numbers between 10000 and 99999 which are divisible by 25. They are elements of the set of numbers of the form 25*k, where k is an integer between 41 and 3999 (inclusive).
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Counting 10000, there are 17999.
The largest 5 digit number is 99999. If this is divided by 11 it leaves a remainder of 9. Therefore the largest 5 digit number divisible by 11 is 99999 - 9 = 99990.
To be evenly divisible by 25 means the number is evenly divisible by 5. All numbers which evenly divide by 25 must therefore end in either "0" or "5".Therefore, as this is a palindrome, we can immediately rule out all numbers other than those between 50,000 and 59,999.In this range we can say that the only palindromic numbers divisible by 25 will end either "25" or "75".This means that there will be 20 numbers which match the criteria.52025, 52125, 52225, 52325, 52425, 52525, 52625, 52725, 52825, 52925 and57075, 57175, 57275, 57375, 57475, 57575, 57675, 57775, 57875, 57975.
100000
90000. With 10 digit palindromes, the last 5 digits are the same as the first 5 digits in reverse, eg 12345 54321. So it comes down to how many 5 digit numbers are there? They are the numbers "10000" to "99999", a total of 99999 - 10000 + 1 = 90000.