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As the first and last digits are fixed to be 3, only the middle 3 digits can change. As repetitions are allowed, each of these digits can be any of the 10 digits {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}. There is a choice of 10 digits for the first, and for each of these choices there is a choice of 10 for the second and for each of these choices there is a choice of 10 for the last digit; thus there are 10 × 10 × 10 = 1000 such possible numbers.
1 option for the first digit, 1 option for the last digit, 10 options for the second digit, 10 options for the third digit, 10 options for the fourth digit. Multiply all these numbers together.
pizza
If repetitions are allows, 325. If no repetitions are allows, then it is 32 x 31 x 30 x 29 x 28.
There are 5*4*3 = 60 such numbers.
There are 5 numbers of 1 digit, 25 numbers of 2 digits, and 75 numbers of 3 digits. This makes 105 numbers in all.
Three ways (I think).
Infinitely many. If you restrict yourself to positive numbers only, but allow repetitions, then there are 15. If you disallow repetitions, only 2.
There are 52.
Yes, numbers are unlimited.
pizza
If repetitions are allows, 325. If no repetitions are allows, then it is 32 x 31 x 30 x 29 x 28.
Considering negative numbers, the amount is unlimited.
There are 5*4*3 = 60 such numbers.
coolkidz
There are 5 numbers of 1 digit, 25 numbers of 2 digits, and 75 numbers of 3 digits. This makes 105 numbers in all.
27 three digit numbers from the digits 3, 5, 7 including repetitions.
543210
system.out.println(" print 1-100 numbers");for(i=0;i