Question

Answer the questions below.

(a) To log on to a certain computer account, the user must type in a 5 -letter password. In such a password, no letter may be repeated, and only the lower case of a letter may be used. How many such 5 -letter passwords are possible? (There are 26 letters in the alphabet.) (b) A pizza parlor has a choice of 12 toppings for its pizzas. From these 12 toppings, how many different 8 -topping pizzas are possible?

Answer 1

ni Answer there we use the concept of permutations, I gu fermutations relation of 'r' things out of 'n' things and arrangement of f' things can be done by ho ways no (nr)! Here 26 detters are there, snud to be selected and arranged. It can be done in 2of ways 26p 26-5)! 21! 262-4893600 261 26 2 으 @ It can be solved thasing the concept of combinations

Gin combinations the number of ways of selecting r different things out of in things in given day n where r = n! & 8 (1.8)!!! n = (m(n-1) (n.2) .... X3 X2x1. Here there will only be selection of & things but not arrangement.

There are 12 toppings, you need to select 8 toppings, atsing the concept of combinations There are 12 different stoppings are possible J + 12 121 121 Cq (12-3) 81 Ol41 T2 = 495 8