How many 5-digit numbers contain all the digits 1, 2, 3, 4 and 5 and have the property that the difference between each pair of adjacent digits is at least 2?

A,B,C,D,A+C,B+C,A+D,B+D represent 8 diffirent natural numbers from 1 to 8. If A is the largest number in the number from 1 to 8.Find A

How many natural numbers are there between 100 and 999 that unit-digit and tens-digit equal hundreds-digit ?

How many different 3-digit whole numbers can be formed using the digits 4, 5, 0 and 8, assuming that no digit can be repeated in a number?

How many different 3-digit whole numbers can be formed using the digits 4, 5, 0 and 8, assuming that no digit can be repeated in a number?

How many natural numbers having three digits such that the tens digit spuared equals the product of other digits and the difference between that numbers and its reversed order is 495

How many whole numbers between 1 and 100 are not divisible by 3 or 11?

how many integer numbers between 200 and 300 are there for which the hundreds digit equals the sum of the other two digits ?

how many integer numbers between 200 and 300 are there for which the hundreds digit equals the sum of the other two digits ?

How many natural numbers between 1000 and 4000 are there for which the thousands digit equals the sum of the other three digits?