The 5 can appear in any of the 4 positions, and for each of those 4 positions the other 3 positions can be filled by any of the other eight digits (1-4, 6-9).
→ 4 x 8 x 8 x 8 = 2048 different numbers with the 5 appearing exactly once.
the largest five digit number that can be formed using the digits 7 and 9 is 97,000
Numbers formed should be of at least 3 digits means they may be of 3 digits, 4 digits, 5 digits or 6 digits. There are 6 choices for digit in the units place. There are 5 and 4 choices for digits in ten and hundred’s place respectively. So, total number of ways by which 3 digits numbers can be formed = 6.5.4 = 120 Similarly, the total no.of ways by which 4 digits numbers can be formed = 6.5.4.3 = 360. the total no. of ways by which 5 digits numbers can be formed = 6.5.4.3.2 = 720. The total no.of ways by which 4 digits numbers can be formed = 6.5.4.3.2.1 = 720. So, total no.of ways by which the numbers of at least 3 digits can be formed = 120 + 360 + 720 + 720 = 1920.
192, including ones containing repeat digits.
-1995
The number of 4 digit codes, using different digits, is 10*9*8*7 = 5040. However, computer passwords can, usually, have repeated digits and, if that is allowed, you can have 104 = 10000 codes.
There are 7,290 different 4-digit numbers that can be formed from the digits 1-9 without repetition.
If the digits are all different then 18. Otherwise, 192.
the largest five digit number that can be formed using the digits 7 and 9 is 97,000
Numbers formed should be of at least 3 digits means they may be of 3 digits, 4 digits, 5 digits or 6 digits. There are 6 choices for digit in the units place. There are 5 and 4 choices for digits in ten and hundred’s place respectively. So, total number of ways by which 3 digits numbers can be formed = 6.5.4 = 120 Similarly, the total no.of ways by which 4 digits numbers can be formed = 6.5.4.3 = 360. the total no. of ways by which 5 digits numbers can be formed = 6.5.4.3.2 = 720. The total no.of ways by which 4 digits numbers can be formed = 6.5.4.3.2.1 = 720. So, total no.of ways by which the numbers of at least 3 digits can be formed = 120 + 360 + 720 + 720 = 1920.
36
10,000
192, including ones containing repeat digits.
-1995
12 numbers.
The number of different 7 digit plates that can be formed where the digits are notrepeated and no zero appears as the first digit is: 544 320.Calculation:Number of different plates = 9 [9P6] = 9 [9!/(9-6)!] = 9x9x8x7x6x5x4 = 544 320.
The number of 4 digit codes, using different digits, is 10*9*8*7 = 5040. However, computer passwords can, usually, have repeated digits and, if that is allowed, you can have 104 = 10000 codes.
how make the answer im don/now