
                ### Instruction: help me answer this question How many words, with or without meaning, can be made from the letters of the word MONDAY, assuming that no letter is repeated, if
(i) 4 letters are used at a time
(ii) All letters are used at a time
(iii) all letters are used, but the first letter is a vowel, think step by step
                ### Assistant: The formulas used are permutations and combinations. , The answer is { (i) The number of 4-letter words that can be formed is 15, (ii) The number of words that can be formed by using all the letters is 720, (iii) The number of words that can be formed by using all the letters, with the first letter being a vowel, is 120 }
