For each number, there are four digits, and for each digit, there are two possibilities for digits: 3 or 4. So the number of 4-digit numbers is 2*2*2*2 = 16. The 4-digit numbers using 3 and 4 are:
3333
3334
3343
3344
3433
3434
3443
3444
4333
4334
4343
4344
4433
4434
4443
4444
three.. 2, 22, 222
24.
120
You would need infinitely many digits to write all numbers. However, to write all whole number (integers) you would need 4243.
13
three.. 2, 22, 222
There are 3*2*1 = 6 of them.
24.
16 numbers.
18
120
You would need infinitely many digits to write all numbers. However, to write all whole number (integers) you would need 4243.
13
11,238,513 of them.
100
Their are far to many to write in here. The link will have the list of actors for Numbers.
If you write all of the counting numbers from 200 to 400,you will write the digit ' 5 ' forty times.