Finding Prime Numbers from 1 to 100

A prime number is a number which _____.

The total number of prime numbers up to $100$ is _____.

Which of the following is a composite number?

Which of the following is a pair of co-primes?

The smallest prime number is _____.

If the smallest sum of money that can be made up of $1-$rupee, $2-$rupee, and $5-$rupee coins is $₹k$, find $k$.

The greatest $2$-digit prime number is _____.

Write the greatest prime number less than or equal to the number.

$78$

Write the greatest prime number less than or equal to the number.

$67$

Write the greatest prime number less than or equal to the number.

$101$

Two prime numbers are always _____.

Is $107$ a prime number? 

$13$ and $31$ are two prime numbers having the same digits $1$ and $3$. Find such pairs of numbers up to $100$.

The sum of two consecutive odd numbers is always divisible by $4$. Is it true? Give examples.

List the numbers which are neither prime nor composite. Can you count them? If yes, how many such numbers are there?

Write all the prime numbers between $100$ and $150$.

Write six pairs of co-prime numbers.

Write all pairs of twin primes less than $20$ and find whether $49$ and $51$ are twin primes or not.

How many even prime numbers are there in the set of natural numbers? List them.

Write all the prime numbers between $30$ and $50$.