There are 11 nines in the numbers from 1 to 100: 9, 19, 29, 39, 49, 59, 69, 79, 89, and 99.
The GCF of all the composite numbers under 100 is 1. For e.g 4 & 9 are composite numbers & their GCF is 1, so if we take other composite numbers along with 4 & 9 the GCF will be 1.
1, 4, 9, 16, 25, 36, 49, 64, 81, 100
There are 720 of them. The three digit counting numbers are 100-999. All multiples of 5 have their last digit as 0 or 5. There are 9 possible numbers {1-9} for the first digit, There are 10 possible numbers {0-9} for each of the first digits, There are 8 possible numbers {1-4, 6-9} for each of the first two digits, Making 9 x 10 x 8 = 720 possible 3 digit counting numbers not multiples of 5.
numbers 1-9 is the answer
Prime squares: 4, 9, 25 and 49
20
To find how many numbers between 1 and 100 are divisible by 9, we can identify the multiples of 9 within that range. The smallest multiple of 9 is 9 (9 x 1), and the largest is 99 (9 x 11). Therefore, the multiples of 9 from 1 to 100 are 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, and 99, totaling 11 numbers.
11 (9, 18, 27, 36, 45, 54, 63, 72, 81, 90 and 99) Those numbers divisible by 9 are the multiple of 9; thus need to know how many multiples of 9 there are between 1 and 100: 100 ÷ 9 = 11 r 1 ÷ last multiple of 9 is 11 × 9 (= 99) → There are 11 - 1 + 1 = 11 numbers between 1 and 100 which are divisible by 9. (They are 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99.)
To find the numbers between 1 and 100 inclusive that are divisible by either 9 or 4, we first determine how many numbers are divisible by 9 and how many are divisible by 4. There are 11 numbers divisible by 9 (9, 18, 27, ..., 99) and 25 numbers divisible by 4 (4, 8, 12, ..., 100). However, we must be careful not to double-count numbers divisible by both 9 and 4 (36, 72). Therefore, the total number of numbers divisible by 9 or 4 between 1 and 100 inclusive is 11 + 25 - 2 = 34.
Just the one which is 9 but there are 20 numbers from 1 to 100 that contain the digt 9
11 times
Twenty of them.
There are nine square numbers including 1 below 100 (1x1...9x9). So, there are 99 - 9 'not square numbers' below 100 which is 90
45 of them.
1*9+2*90+3*1=192
9
Twenty of them from 9 to 99