Question

Express the number 24 as the sum of two odd primes.

Answer 1

Hint: We will start our exploration of getting 24 as the sum of two odd primes with the sum of 1+23 and then move further step by step till we get our answer. We will be using a trial and hit method.

Complete step-by-step answer:
Before proceeding with the question we must know about prime numbers and odd prime numbers.
A prime number is a number divisible only by 1 and itself. Every prime number except 2 is an odd prime number.
Case 1- 24 is the sum of 1 and 23. We cannot take this as the answer because 1 is neither prime nor composite.
Case 2- 24 is the sum of 2 and 22. We cannot take this as the answer because 2 is not an odd prime number.
Case 3- 24 is the sum of 3 and 21. We cannot take this as the answer because 21 is not a prime number.
Case 4- 24 is the sum of 4 and 20. We cannot take this as the answer because 4 is an even and composite number and 24 is not a prime number.
Case 5- 24 is the sum of 5 and 19. We can take this as the answer because 5 and 19 both are odd prime numbers.
Hence 24 is the sum of 5 and 19.

Note: Knowing the definition of prime numbers and odd prime numbers is the key here. Trial and hit method is best suited for this type of question. We can commit a mistake in a hurry in case 1 thinking 1 also as an odd prime number and 23 is already an odd prime number.