How many different numbers which are smallerr than `2xx10^(8)` and are divisible by 3, can be written by means of the digits 0,1 and 2?

Find the number of natural numbers which are less than 2xx10^(8) and which can be written by means of the digit 1 and 2 .

How many numbers divisible by 125 can be written by using all the digits 2,3,8,7 and 5 exactly once?

How many 2-digit numbers are divisible by 3?

How many numbers of 4 digits greater than 5000 and divisible by 5 can be made by using the digit 0,1,3,5 and 7. Repetitions of numbers is not allowed.