At an election, a voter may vote for any number of candidates, not greater than the number to be elected. There are 10 candidates and 4 are of be selected, if a voter votes for at least one candidate, then the number of ways in which he can vote is

If the letter of the word SACHIN are arranged in all possible ways and these words are written out as in dictionary, then the word SACHIN appears at serial number

How many ways are there to arrange the letters in the word GARDEN with vowels in alphabetical order

The number of ways of distributing 8 identical balls in 3 distinct boxes so that none of the boxes is empty is