Probability

Question

Q1, a bowl has 3 white and 6 green balls in it. What is the probability of selecting 4 white balls in a row, a. if the selection is done with replacement? b. if the selection is done without replacement? Q2, What is the probability of your ticket being picked 3rd in a drawing with 20 tickets?

Answer 1

Q2.

 

Believe it or not the probability is the same whether you ask if the ticket is picked 1st, 2nd,3rd,... or last.

 

So with that gigantic hint what's the answer?

 

If you don't believe me comment back i'll explain further.

Answer 2

Q1. a.

(4/7)(4/7)(4/7)(4/7)

256/2401

 

Q1. b.

Impossible, you only have 3 white balls!