1. Add the three numbers on the right of 43 to form a five-digit number, so that it can be divisible by 3, 4 and 5, and find the smallest five-digit number.

2. The greatest common divisor of two integers A and B is C, and the least common multiple is D. It is known that C is not equal to 1, nor to A or B, and C+D = 187. What is A+B?

3. A natural number is a multiple of 3 and 4, including 1, and itself * * * has 10 divisors, so what is this natural number?

There is a four-digit number divided by its digits to get four integer quotients. The sum of these four quotients is still this four-digit number. How many four-digit numbers meet the requirements?

5. There are less than 100 students in a school, including more than 4/7 boys and more than 2/5 girls. How many boys and girls are there?

6. There are four identical white pieces and four identical black pieces. One person takes several pieces of the same color at a time, or takes the same number of two colors. How many ways can I get them all?