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221
11 and 18
11 and 16.
11 is a tricky one, but this is how:if the sum of every other digit minus the sum of all the other digits equals a multiple of 11example:Q: Is 164725 divisible by 11?A: Yes. and this is why... first you take every other digit 164725, then add them 6+7+5=18. Now take the rest of the numbers 164725 and add them, 1+4+2=7. After that subtract them, 18-7=11, and 11 is a multiple of 11 (11x1=11).
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There are 199 palindromic numbers between 0 and 1000. These include single-digit numbers (0-9), which total 10, and two-digit numbers (11, 22, ..., 99), which add up to 9. Additionally, there are 90 three-digit palindromic numbers, ranging from 101 to 999, that follow the format aba (where a and b are digits). Thus, the total is 10 (single-digit) + 9 (two-digit) + 90 (three-digit) = 109 palindromic numbers.
The digital root of a number is found by repeatedly summing its digits until a single digit is obtained. For the number 11, you add the digits: 1 + 1 = 2. Since 2 is a single digit, the digital root of 11 is 2.
You can select 12 numbers for the first digit, 11 numbers for the second digit, and 10 numbers for the third digit; so 12*11*10 = 1320 sets of 3 numbers can be made out of 12 different numbers.
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221
99990 Note that if you add 11 to my answer you get a 6-digit number therefore it must be the largest 5-digit whole multiple of 11.
Eleven digit numbers are those in the range between 9,999,999,999 and 100,000,000,000 exclusive. There are 90,000,000,000 of these.
11
11
Palindromic numbers between 1 and 1000 are numbers that read the same forward and backward. The palindromic numbers in this range include single-digit numbers (1 to 9), two-digit numbers like 11, 22, 33, up to 99, and three-digit numbers such as 101, 111, 121, up to 999. Specifically, the three-digit palindromes follow the pattern ABA, where A and B are digits. In total, there are 199 palindromic numbers between 1 and 1000.
There are more 12-digit palindromic numbers than 11-digit palindromic numbers. This is because the number of possible 12-digit palindromic numbers is greater than the number of possible 11-digit palindromic numbers. In general, the number of palindromic numbers of length n is 9 * 10^((n-1)/2), so for 11-digit palindromic numbers, there are 9 * 10^5 = 900,000 possibilities, while for 12-digit palindromic numbers, there are 9 * 10^6 = 9,000,000 possibilities.
The two 2-digit numbers that multiply to make 176 are 11 and 16. When you multiply 11 by 16, you get 176 (11 × 16 = 176). These are the only two-digit integers that satisfy this condition.