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) =
4 6/9 + 7/9 = 5 3/9
Hope this helps
Answer:
5 3/9 or 5 1/3
A ray is a line that has a begining point, but no end point
a ray is 1 dimentional, it only goes one direction, left and right
a plane is 2 dimentional and extends indefinitely
it goes left and right and up and down
think of it like this
you have a piece of paper with no height
you draw a line starting at a point on the paper and it goes infinitely in the other direction
the paper is a plane, the line on it that has a starting point is the ray
