24
9
You can select 9 numbers for the first digit, 8 numbers for the second digit, and 7numbers for the third digit; so 504 (e.g. 9*8*7) different three digit numbers can be written using the digits 1 through 9.
No 5291 is not a prime using 2 numbers. It is a prime using three numbers.
89,999 different numbers i guess
9,999,876 is the greatest seven-digit number using four different digits.
You have seven different digits (symbols) to choose from, so you can form seven different one digit numbers and 7×7=72=49 different two digit numbers.
1000
1 x ((7 x 3) + 3) = 24
9
You can select 9 numbers for the first digit, 8 numbers for the second digit, and 7numbers for the third digit; so 504 (e.g. 9*8*7) different three digit numbers can be written using the digits 1 through 9.
No 5291 is not a prime using 2 numbers. It is a prime using three numbers.
89,999 different numbers i guess
There are 3*2*1 = 6 of them.
3.1415926
9,999,876 is the greatest seven-digit number using four different digits.
6 possible 3 digit combonations
Using 1, 2, and 3, you can make 27 whole numbers.