The Number of Elements in a List
If m and n are integers and m ≤ n, then there are n − m + 1 integers from m to n
inclusive.
m = 100, n = 999
according to theorem above
999 - 100 + 1 = 900
The 3 digit numbers under 500 are 100 through 499.
999-111=888 888 3 digit numbers can be made with numbers between 1 - 9
There are 3 values (1, 2, 3) for each of the 4 digits. Therefore, there are 3*3*3*3 or 81 four digit numbers that can be formed.
If you can repeat a digit, there are 27. If you can't repeat a digit, there are only 6.
The smallest 3-digit multiple of 7 is 105 = 15*7 The largest 3-digit multiple of 7 is 994 = 142*7 So there are 142-14 = 128 3-digit multiples of 7, ie 128 3-digit numbers that are divisible by 7.
None. 3 digit numbers are not divisible by 19 digit numbers.
There are 151 3-digit numbers that are divisible by 6.
There are 84 such numbers.
The 3 digit numbers under 500 are 100 through 499.
3 digit numbers are lessthan 4 digit numbers
210
450 whole numbers.
100
999-111=888 888 3 digit numbers can be made with numbers between 1 - 9
There are 84 of them.
450
90