CHAPTER 3. COMBINATORICS
Exercise 1 Page 88
Four people are to be arranged in a row to have their picture taken. In how many ways can this be done?
Solution
Position1 can be taken by all the four students
Position2 can be taken by rest of the three students
Position3 can be taken by rest of the two students
Position4 can be taken by rest of the one student
Thus the total combinations of arrangements possible are:- \[4*3*2*1 = 24\] Or, We can say the total number of combinations are 4!
## [1] 24