Aptitude Day 117

Problems on Permutations and Combinations:

1. In how many different ways can the letters of the word 'REPRESS' be arranged? 

Solution:
               The given word has 7 letters and the letters R, E and S are repeated twice. Hence,

               7!/ 2! 2! 2! = 7*6*5*4*3*2! / 2! (4)
                                 = 7*6*5*3
                                 =  630. 

2. How many words can be formed by using all the letters of the word,'SQUEEZE'?

Solution:
               The given word has 7 letters and E is repeated thrice. Hence,

               7! / 3! = 7*6*5*4*3!/3!
                          = 840.