Question

statistics and probability question below.

Answer 1

At a shopping mall, one ticket is given to every customer who spends $1000 or more.
With the ticket, the customer will be invited to draw a ball from the lucky draw box
containing 35white and 5orange balls.
-If the first draw is an orange ball, the customer wins a special prize. The draw ends
and the ball is not replaced.
-If the first draw is a white ball,the ball is replaced in the box and the customer is
invited to draw a second time
-If the second draw is an orange ball, the customer wins the special prize. The draw
ends and the ball is not replaced.
-If the second draw is a white ball, the ball is replaced in the box and customer
walks away with nothing.

The lucky draw is over when all the 5orange balls have been drawn by customers.

(a) If none of the special prizes have been won yet, find the probability that the
customer with the ticket
(i) draws 2 white balls
(ii) wins the special prize
(b)If only one orange ball is left, find the probability of winning the special
prize.
(c) considering your answers and the format of the lucky draw, will it take the next
customer a longer/shorter/same amount of time to win the special prize? Briefly
explain your answer.

Answer 2

considering one customer i think like this:
if no prize is won yet therefore all the 5 orange ball are still in the box...(i) there is only one way of drawing 2 white ball that is if the first ball is with and the second one white as well

Answer 3

probability of drawing white ball is 35/N where N is total num of balls
the only way you do not win a prize is if you draw a white ball twice in a row
therefore
probability of winning prize is 1-(35/N)^2

N starts at 40 then decreases as more people win prizes
as N decreases, the probability of winning decreases...so the first person has better chance of winning prize then last person