500
40 palindromes.
505,515,...595 -- 10 p. numbers 606,616,...696 -- 10 p. numbers notice the pattern --- looks like there are 50
40. There are 400 numbers between 100 and 500 and one in every ten ends in 5.
157 of them.
500
40 palindromes.
There are 9 palindromic numbers between 400 and 500. A palindromic number reads the same forwards and backwards. The palindromic numbers in this range are 404, 414, 424, 434, 444, 454, 464, 474, and 484.
505,515,...595 -- 10 p. numbers 606,616,...696 -- 10 p. numbers notice the pattern --- looks like there are 50
40. There are 400 numbers between 100 and 500 and one in every ten ends in 5.
500
There are (500-100)/2 = 200 numbers divisible by 2 between 100 and 500 counting 100 but not 500. Of these (500-100)/8 = 50 are divisible by 8. So there are 150 numbers between 100 and 500 divisible by two but not by 8. By relative primeness exactly 50 out of these 150 are divisible by 3 and therefore these 50 are exactly the ones divisible by 6 but not by 8.
157 of them.
They are from 11 squared to 22 squared making a total of 12 square numbers between 100 and 500
727. The smallest palindromic number greater than 500 independent of primicity is 505.
There are 67 numbers between 100 and 500 divisible by 6. The first number greater than 100 divisible by 6: 100 ÷ 6 = 16 r 4 → first number divisible by 6 is 6 × 17 = 102 Last number less than 500 divisible by 6: 500 ÷ 6 = 83 r 2 → last number divisible by 6 is 6 × 83 = 498 → all multiples of 6 between 17 × 6 and 83 × 6 inclusive are the numbers between 100 and 500 that are divisible by 6. → there are 83 - 17 + 1 = 67 such numbers.
If you mean 3-digit numbers whose digits are in decreasing order, then the answer is 20.