How many words can be formed by writing letters in the word CROWN in different order?

How many 4 letter words can be formed using letters in the word MADHURI if (a) letters can be repeated (b) letters cannot be repeated.

How many 5 letter words can be formed using letters in the word NIRMAL if (a) letters can be repeated (b) letters cannot be repeated

How many words can be formed from the letters of the word COURTESY, whose first letter is C and the last letter is Y?

How many words can be formed with the letters of the word MATHEMATICS by rearranging them

How many two letter words can be formed using letters from the word SPACE, when repetition of letters (i) is allowed, (ii) is not allowed?

Find the number of words that can be formed by using all the letters in the word REMAIN. If these words are written in dictionary order, what will be the 40th word?