where le Starts his deliv ns Diamand lran3pU eries or ent ro

where le Starts his deliv ns Diamand lran3pU eries or ent routes are possible if David does not care where ne s known to her, 7 will make money, and srandomly picking 3 stocks from a list of 10. Unknown to her, 7 will m make money? Picks 3 that all.lose money? -CL ,( 4- hes his trip? ney, and 3 ney? Picks 2 that 2 lose money. What is the probability that Nicole picks only 1 tht makes money? Picke g that has ten floors (not counting the basement),. Suppose further that there is an equal chance that a p elevator at any of the ten floors, and that where any one person exits the elevator is 23) Suppose that ten people enter an elevator at the basement of a building that has te ersonexis erson exits the independent of where any other person exits the elevator. What is the probability that exactv that exactly one person exits the elevator at each of the ten floors? l0 24) Suppose that there are eight seats in a row and there are eight people to sit in the eight seats, one person per seat. How many seating arrangements of the eight seats and eight people are there? 304

Solution

A)

Note that the number of permutation of n objects on a line is n!

Here, n = 8. Hence, there are

#ways = 8! = 8*7*6*5*4*3*2*1 = 40320 seating arrangements [ANSWER]

B)

We can treat Kirstin and Kristin as 1 body and thus, we have 7 people. There are 7! = 5040 ways.

We multiply this by 2, as we can permute the twins.

Thus,

#ways = 10080 [ANSWER]

c)

We can treat the triplets as 1 body, and so we permut just \"6 people\". There are 6! = 720 ways to do that.

We multiply this by 3! = 6, as we can permut the triplets.

Hence, there are 720*6 = 4320 ways [answer]