Find the number of n-digit numbers
27218
How to use stars and bars for solving number of integral solutions to an equality?
80908
Algorithm to calculate the number of divisors of a given number
40821
Number formation from given digits
59788
Let T = {1000,1001...,9999}. How many numbers have at least one digit that is 0...
59073
Method for Counting the Divisors of a number
128220
How many five-digit numbers can be formed using digits $0, 1, 2, 6, 7, 8,9$ which are divisible by $3$ and $5$?
119031
How many 6 digit numbers are possible with no digit appearing more than thrice?
48605
Distinct digits in a combination of 6 digits
32039
What are the trailing number of the zeroes in the given integer
52043
Number of binary numbers with two consecutive zeros
148703
Permutations with repeating digits
52348
Counting the number of surjections.
60915
Count number of 1's in binary representation
144079
Find Total number of ways out of N Number taking K numbers every M interval
132921
Counting problem, number of moves
115145
Show that $n-m$ is a multiple of 9 when $n$ and $m$ have same digits
65328
Counts and skips the numbers that have digits divisible by 3 (change in base method)