Q. If the four letter words (need not be meaningful ) are to be formed using the letters from the word such that the first letter is and the fourth letter is , then the total number of all such words is :

 3970  234 JEE MainJEE Main 2016Permutations and Combinations Report Error

Solution:

M, EEE, D. I, T, RR, AA, NN

Two empty places can be filled with identical letters [EE, AA, NN] 3 ways
Two empty places, can be filled with distinct letters [M, E, D, I, T, R, A, N]
Number of words