Prime and Composite Numbers

Express the number $31$ as the sum of three odd primes.

Express the number $21$ as the sum of three odd primes.

Write seven consecutive composite numbers less than $100$ so that there is no prime number between them.

Give three pairs of prime numbers whose difference is $2.$

Express $18$ as the sum of two odd primes.

Express $36$ as the sum of two odd primes.

All even numbers are composite numbers.

The smallest composite number is _____.

The smallest prime number is _____.

 A number which has more than two factors is called a _____ number.

 A number which has only two factors is called a _____ number.

Write five pairs of prime numbers less than $20$ whose sum is divisible by $5.$

 If $61$ is expressed as the sum of two odd primes, write the greatest odd prime among all the possible combinations of odd primes.

If $53$ is expressed as the sum of three odd primes, write the greatest odd prime among all the possible combinations of odd primes.

Which of the following numbers are prime?

If $24$ can be expressed as the sum of two odd primes, write the greatest odd prime among all the possible combinations of odd primes.

If $44$ is expressed as the sum of two odd primes, write the smallest odd prime among all the possible combinations of odd primes.

What is the greatest prime number between $1$ and $10?$

The numbers $13$ and $31$ are prime numbers. Both these numbers have same digits $1$ and $3.\mathit{}$ Find such pairs of prime numbers up to $100.$

 All even numbers are composite numbers.