Find all the two digit prime numbers neither of whose digits are prime.
well, prime digits are 1,2,3,5,7
The first number then is 44, then 46, 49, then 64, you finish.
okay, thank you
is 48 included in the numbers you listed?
48 is not a prime number.
http://www.jiskha.com/display.cgi?id=1300106041
To find all the two-digit prime numbers whose digits are not prime, we can check each number from 10 to 99 and eliminate any number that has a prime digit.
Start by listing down all prime digits:
2, 3, 5, 7
Now, iterate through all two-digit numbers from 10 to 99:
10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, ...
For each number, check if both digits are prime. If any digit is prime, eliminate the number from the list. We can use the list of prime digits we generated earlier for this check.
Let's go through the process step by step:
Step 1: List the prime digits: 2, 3, 5, 7
Step 2: Iterate through all two-digit numbers:
- 10: Check the digits 1 and 0. None of them are prime, so this number remains in the list.
- 11: Both digits are prime (1 is not prime). Eliminate this number.
- 12: Both digits are prime. Eliminate.
- 13: Both digits are prime. Eliminate.
- 14: The first digit is not prime. Keep this number.
- 15: The second digit is not prime. Keep.
- 16: Both digits are prime. Eliminate.
- 17: Both digits are prime. Eliminate.
- 18: The second digit is not prime. Keep.
- 19: Both digits are prime. Eliminate.
- 20: The first digit is not prime. Keep.
- 21: The second digit is not prime. Keep.
...
Continue this process until you iterate through all the numbers from 10 to 99. You will be left with a list of two-digit prime numbers neither of whose digits are prime.
The final list of two-digit prime numbers with non-prime digits is: 14, 15, 18, 20, 21, 24, 25, 28, 30, 31, 34, 35, 38, 40, 42, 43, 46, 48, ...