Pairs of numbers of the form $(6k-1)$ and $(6k+1)$ are twin primes in case of$k=\left\{1,2,3\right\}$ . Is this statement true or false?

What is the product of twenty-one even numbers and thirty odd numbers?

What is the absolute value of $-10?$

How many rational numbers exist between any two rational numbers?

Is $\mathrm{\pi }$ a rational or an irrational number?

 What is the multiplicative inverse of $a$, where $a\ne 0?$

The $LCM$ of $a$ and $b$ is $x$. What is the $LCM$ of $ma$ and $mb$?

What is the $GCD$ of $ma$ and $mb$, if the $GCD$ of $a$ and $b$ is $x?$

How many prime numbers are there between $1$ and $50?$