How to make the nine numbers 123456789 into two four digit numbers, one of which is a multiple of the other, and nine digits cannot be repeated This is the homework of grade three in primary school. There are 123456789 nine numbers. One four digit number is multiplied by one one digit number. The other four digit number is nine numbers. It can't be repeated

How to make the nine numbers 123456789 into two four digit numbers, one of which is a multiple of the other, and nine digits cannot be repeated This is the homework of grade three in primary school. There are 123456789 nine numbers. One four digit number is multiplied by one one digit number. The other four digit number is nine numbers. It can't be repeated

1738 * 4 = 6952
1963 * 4 = 7852

How many five digit numbers can be made up of 1, 2, 3, 4, 5 and 6 that are not repeated and are multiples of 6?

The prime number of 6 is 2,3, so if you want to be divisible by 6, you need to be divisible by both 2 and 3. You know, if you add up the number of digits to be divisible by 3, then it can also be divisible by 3. For example, 372:3 + 7 + 2 = 12, 12 can be divisible by 3, so 372 can also be divisible by 3

How many six digit numbers can be composed of numbers 0, 1, 2, 3, 4 and 5 without repetition

Let's use the method of permutation and combination. First of all, this is the content of the high school textbook in the new curriculum standard. There is an example in the book. It's not easy to play the upper corner mark and the lower corner mark. Let's make an agreement: permutation is a, combination is C, the lower corner mark is written before (for example, c-5-3 read as C 53, the lower corner mark is 5, the upper corner mark is 3), "^" is the index sign, and "!" is the multiply sign