Help! Will Give Medal
Nine door prizes are to be awarded at a club meeting. There are 100 tickets in the box, and one of them is yours. A ticket is drawn, the prize is awarded, and the ticket is placed back in the box. This continues until all nine prizes are awarded.
(a) Find the probability your ticket is drawn once.
(b) Find the probability your ticket is drawn twice.

Question

Help! Will Give Medal
Nine door prizes are to be awarded at a club meeting. There are 100 tickets in the box, and one of them is yours. A ticket is drawn, the prize is awarded, and the ticket is placed back in the box. This continues until all nine prizes are awarded. 
(a) Find the probability your ticket is drawn once. 
(b) Find the probability your ticket is drawn twice.

anonymous · Answer

I'm going to have to guess here... 
1/100 = .01
.01/9
.02/9 would be the second answer by that logic.

anonymous · Answer

a) there are (9C1) ways your ticket can be drawn. So
P = (9C1) (1/100) (99/100)^8

b) same argument
P = (9C2) (1/100)^2 (99/100)^7

anonymous · Answer

Thank You