In how many different ways can the letters of the word 'LEADING' be arranged in such a way that the vowels always come together?

In how many different ways can the letters of the word 'CORPORATION' be arranged so that the vowels always come together?

In a group of 6 boys and 4 girls, four children are to be selected. In how many different ways can they be selected such that at least one boy should be there?

One of the solution for the equation 15x $$\equiv$$ 6(mod 21) is

For Euler $$\phi$$ - function $$\phi$$ (6) is equal to

Number of integers, which are less than 108 and prime to 108 is

The unit digit of $$2^{100}$$ is

If 30 dictionaries in a library contain a total of 613327 pages, then one of the dictionaries must have atleast ____ pages.

gcd(56,72)is