In how many ways can the letters of the word ‘DELHI’ be arranged so that the vowels occupy only even places?
All the letters in the word ‘DELHI’ are distinct with 2 vowels (E, I) and 3 consonants (D, L, H).
In five letter words, even place can occupy ‘E’ and ‘I’ in 2! Ways and remaining 3 places can occupy consonants D, L, H in 3! Ways.
So no. of words = (3!) × (2!) = 12.
Ten persons, amongst whom are A, B and C, are to speak at a function. If n is the number of ways in which it can be done if A wants to speak before B, and B wants to speak before C find n/800.
Find the largest such that
Find the largest integer n for which 35! Is divisible by 3n.
The number of natural numbers which are smaller than 2 × 108 and which can be written by means of the digits and 2 is ………..
Find the exponent of 2 in 50!?
Find the number of zeroes in 100!
A city has 12 gates. In how many ways can a person enter the city through one gate and come out through a different gate?
Find the number of different words which can be formed using all the letters of the word ‘HISTORY’.
In how many ways 5 different red balls, 3 different black balls and 2 different white balls can be arranged along a row?