# Probability and Events (I don't quite understan the answer)

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1. Oct 7, 2015

### Matejxx1

1. The problem statement, all variables and given/known data
An only child Urška puts 3 pieces of paper into a bag : on each piece of paper is written a name of one of her classmates :David,Niko,Dejan (those are the 3 names): She then randomly picks 2 pieces of paper from the bag and checks them
Match the statements on the right with the ones on the left
We have to mach the letters with the numbers
2. Relevant equations
none

3. The attempt at a solution
A: on one of the chosen papers is the name David
B:On one of the papers is written the name of Urška's brother
C:she pick 2 pieces of paper
D:3
E: on none of the chosen pieces of paper is the name Dejan

1:elementary event
2:experiment
3:impossible event
4:Compound event
5: numbers of possible result

and so I got
A4
B3
C2
D5
E1
What I don't understand is why is A (on one of the chosen papers is the name David ) a compound event
why can't it be an elementary event

Last edited: Oct 7, 2015
2. Oct 7, 2015

### andrewkirk

Think about picking out the first piece of paper and picking out the second. Are they different events?

3. Oct 7, 2015

### Matejxx1

Well yes since the name on the first piece must be different from the second one, however I still don't quite get the answer.

4. Oct 7, 2015

### Matejxx1

Ah I think I got it mind telling me if this way of thinking is correct
if we pick the piece of paper with the name David, we must also check the 2nd piece to figure out if it is Niko or Dejan
However if we look E(on none of the chosen pieces of paper is the name Dejan) because we know which name was not picked up we know which two were.