The product of the digits of 3214 is 24. How many distinct four-digit positive integers are such that the product of their digits equals 24?
The number of ways that you can arrange four different digits is 4 x 3 x 2 x 1 = 24 ways.
There are 64 ways for the product of a 4-digit number to equal 24
6 x 4 x 1 x 1 = 12 numbers
6 x 2 x 2 x 1 = 12 numbers
4 x 3 x 2 x 1 = 24 numbers
8 x 3 x 1 x 1 = 12 numbers
3 x 2 x 2 x 2 = 4 numbers
Add all of them up, and you get 64.
because you guys had different answers, I did it myself and I found idk ( I didn't count) numbers of which 24 numbers are distinct.
1138, NO
1183, NO
1146, NO
1164, NO
1226, NO
1262, NO
1234, --------------------------- 1
1243, --------------------------- 2
1318, NO
1381, NO
1324, ---------------------------- 3
1342, ----------------------------- 4
1416, NO
1461, NO
1423, ------------------------------ 5
1432, ------------------------------ 6
1614, NO
1641, NO
1622, NO
1813, NO
1831, NO
2126, NO
2162, NO
2134, ----------------------------- 7
2143, ----------------------------- 8
2216, NO
2261, NO
2223, NO
2232, NO
2314, -------------------------------- 9
2341, -------------------------------- 10
2322, NO
2413, -------------------------------- 11
2431, -------------------------------- 12
2612, NO
2621, NO
3118, NO
3181, NO
3124, -------------------------------- 13
3142, --------------------------------- 14
3214, -------------------------------- 15
3241, -------------------------------- 16
3222, NO
3412, -------------------------------- 17
3421, --------------------------------- 18
3811, NO
4116, NO
4161, NO
4123, ---------------------------------- 19
4132, ------------------------------------ 20
4213, ------------------------------------- 21
4231, ------------------------------------- 22
4312, ------------------------------------ 23
4321, ------------------------------------ 24
4611, NO
6114, NO
6141, NO
6122, NO
6212, NO
6221, NO
6411, NO
8113, NO
8131, NO
8311, NO
This was just like a check that geno's answer was correct... .
thus there are 24 ways.