Five letter words, having distinct letters, are to be constructed using the letters of the word 'EQUATION' so that each word contains exactly three vowels and two consonants. How many of them have all the vowels together?

What is the number of ways in which an examiner can assign 10 marks to 4 questions, giving not less than 2 marks to any question?

In a 12 storied building, 3 persons enter a lift cabin. It is known that they will leave the lift at different floors. In how many ways can they do so if the lift does not stop at the second floor?

If the total number of m-element subsets of the set A = {a₁, a₂, ..., a_n} is k times the number of m element subsets containing a₄, then n is