Number Theory T...

If $$i^2 = - 1$$, then the value of $$\displaystyle \sum^{200}_{n = 1} i^n $$ is

Which is the least prime number ?

How many prime numbers are there between 10 and 30?

By Goldbach's conjecture, every even number greater than 4 can be expressed as a sum of

If $$z = \displaystyle \frac{(3 + 4i)(5 - 7 i)}{(7 + 5i)(4 - 3i)}$$ then $$|z| = ?$$

Which of the following is not a composite number ?

If 2009 = $$\displaystyle p^{a}.q^{b}$$ where p and q are prime numbers then find the value of p + q

1+$$i^2 + i^4 + i^6 + ........+ i^{2n}$$ is

The number of prime numbers between $$0$$ and $$20$$ is

Which of the following is not a composite number?