Question

Write a for loop that iterates from 1 - 20. Prints "prime" for all prime numbers, "even" for all even numbers, and "odd" for all odd numbers. I cannot figure out how to test for the prime numbers. Can you please give a step-by-step explanation? Note: consider 2 as an even number and 1 & 3 as odd

Answer 1

To determine if a number is prime, even, or odd within a for loop from 1 to 20, check divisibility by 2 for even numbers, iterate through possible divisors to find prime numbers, and label the rest as odd, considering that 2 is both prime and even.

Step-by-step explanation:

To write a for loop that iterates from 1 to 20, and prints whether a number is prime, even, or odd, you need to know:

• Even numbers are divisible by 2.
• Odd numbers are not divisible by 2.
• A prime number is a number greater than 1 that has no positive divisors other than 1 and itself.

Here is a step-by-step explanation:

1. Create a for loop that starts at 1 and ends at 20.
2. Within the loop, check if the number is even by using the modulus operator (%). If number % 2 == 0, the number is even.
3. If the number is not even, check if it is prime. A prime number check usually involves iterating from 2 to the square root of the number and checking if it has any divisors.
4. If the number is not even and not a prime, it must be odd.
5. Print the appropriate label for each number ('prime', 'even', 'odd').

Remember that the number 2 is a special case where it is considered even and also prime.

Answer 2

To determine prime numbers in a for loop from 1 to 20, check for divisibility by numbers other than 1 and itself. Print 'prime' for prime numbers, 'even' for even numbers, and 'odd' for odd numbers. Use the modulus operator to check for even or odd.

Step-by-step explanation:

To determine whether a number is prime, you need to check if it is divisible by any number other than 1 and itself. If a number is divisible by any other number, it is not prime and should not be labeled as such.

• Start by creating a for loop that iterates from 1 to 20.
• For each number, check if it is divisible by any number from 2 to the number itself divided by 2.
• If it is divisible by any number other than 1 and itself, label it as not prime.
• If it is not divisible by any number other than 1 and itself, check if it is even or odd using the % (modulus) operator.
• If the number is even, print 'even'.
• If the number is odd, print 'odd'.
• If the number is not prime, print 'not prime'.