Answer:
1,
,
.
Step-by-step explanation:
probability = 
Total number of persons in the party = n
a) Pr ( every person gets their phone back) = Pr (each person picks his phone ) multiplied by number of person
=
× n = 1.
No of first m persons to pick = m
No of last m persons to pick = 1 - m
b) Pr (first m persons to pick each gets their phones back) = 
c) Pr( first m persons get a phone belonging to last m persons) = 
D=20/3 or in decimal form d=6.666, it keeps going
Answer:
Please find attached pdf
Step-by-step explanation: