The ratio of the number of one-digit prime numbers to the number of one-digit composite numbers is one to one. The one-digit prime numbers are 2, 3, 5, and 7. The one-digit composite numbers are 4, 6, 8, and 9. Therefor, the ratio is 4:4, which simplifies to 1:1.
There are four of each.
Only one positive prime number has a 5 in the ones digit. That prime number is 5. All other numbers with a 5 in the ones digit are composite because they will be divisible by 5.
There are 21 two-digit prime numbers. The first two-digit prime number is 11, and the last two-digit prime number is 97. Prime numbers are numbers greater than 1 that are only divisible by 1 and themselves.
17, 37, 47, 67, 97
2, 3, 5, and 7 are the only one-digit prime numbers.
The ratio of the number of one-digit prime numbers to the number of one-digit composite numbers is one to one. The one-digit prime numbers are 2, 3, 5, and 7. The one-digit composite numbers are 4, 6, 8, and 9. Therefor, the ratio is 4:4, which simplifies to 1:1.
There are four of each.
There are 21 two-digit prime numbers.
There can only be one largest two-digit prime number.
There are 17 such numbers.
For a 2-digit prime number (which are all odd) to be the sum of two prime numbers, one of the prime numbers will have to be 2. That means the difference between the sum and the other addend will have to be 2. Prime numbers that differ by 2 are called twin primes. There are six pairs of 2-digit twin primes. Your numbers are 13, 19, 31, 43, 61 and 73.
73 is the largest two-digit number that is prime and has prime numbers for both of its digits.
There are only two prime numbers that are consecutive numbers, 2 and 3. Their product is 2 x 3 = 6. The first prime numbers are 2, 3, 5, and 7 and the only two consecutive prime numbers whose product is a single digit are 2 and 3. (The next two consecutive prime numbers, 3 and 5, have a two-digit product.)
Only one positive prime number has a 5 in the ones digit. That prime number is 5. All other numbers with a 5 in the ones digit are composite because they will be divisible by 5.
there are 4
There are 21 two-digit prime numbers. The first two-digit prime number is 11, and the last two-digit prime number is 97. Prime numbers are numbers greater than 1 that are only divisible by 1 and themselves.