What is the sum of all digits which appear in all the integers from 10 to 100?

What is the number of numbers of the form 0.xy, where x and y are distinct non-zero digits?

The sum of three consecutive integers is equal to their product. How many such possibilities are there?

15 × 14 × 13 × … × 3 × 2 × 1 = 3 m × n 12. 15 × 14 × 13 × … × 3 × 2 × 1 = 3 m × n Where m and n are positive integers, then what is the maximum value of m?

Consider the following statements in respect of two natural numbers p and q such that p is a prime number and q is a composite number: 1. p x q can be an odd number. 2. q / p can be a prime number. 3.…

Let p be a two-digit number and q be the number consisting of same digits written in reverse order. If p x q = 2430, then what is the difference between p and q?

What is the smallest number greater than 1000 that when divided by any one of the numbers 6, 9, 12, 15, 18 leaves a remainder of 3?