start at 508 and add 10 until you reach 998. also include 580 680 780 and 980.
153
There are exactly 50 even numbers if you include 100. There are exactly 50 odd numbers if you include 1.
There are 120 of them.
How many numbers are divisible by 9 between 5 and 1000²
There are 9 digits in the numbers from 1 to 9. There are 180 digits in the numbers from 10 to 99 (2 x 90). There are 441 digits in the numbers from 100 to 246 (3 x 147). Therefore, the last number David wrote before stopping to rest is 246.
a 8-digits palindromic number is a number consisting of a 4-digits number written and then written backward, i.e. 1234 4321 so there are as many palindromic 8-digits numbers as 4-digits numbers so from 1000 to 9999, so there are 8999 palindromic 8 digits number (I assumed that 00011000 is not to be considered as a valid 8 digit number)
it s 243..
123
Not couting 1 and 1000, there would be 998 numbers.
252 of them.
16
91.
solution: we know that there are 25 prime numbers are between 1-100 and 168 prime numbers less than 1000. 100 x 100=10000(5 digits) 999 x 999=998001(6 digits) 1000 x 1000=1000000(7 digits) so our answer should be same as the number of prime numbers between 100 to 999. hence, 168-25=143. 143 prime numbers will be there less than 1000 whose square has 5 or 6 digits.
174
There are exactly 50 even numbers if you include 100. There are exactly 50 odd numbers if you include 1.
999 are whole.
Numbers above 99 and under 1000 are 3-digits, all 900 of them.
1,234,567 2,345,678 3,456,789