Plase help ! Thank you very much! 28. A couple plans to have three children. The
ID: 3255559 • Letter: P
Question
Plase help ! Thank you very much!
28. A couple plans to have three children. The chance they have a girl is 0.8. The gender of one child is independent of the gender of another child. What is the probability of having all girls when having three children?
0.008
0.096
0.384
0.512
31. The chance of winning on the type of lottery tickets you purchase is 0.05 or 1 in 20. You know to stop after you win, so this will be a geometric setting. You will play each Saturday until you win. What is the probability of winning on the third ticket?
0.05
0.0475
0.0451
0.0429
32. The chance of winning on the type of lottery tickets you purchase is 0.05 or 1 in 20. You know to stop after you win, so this will be a geometric setting. You will play each Saturday until you win. What is the probability of winning on the second ticket?
0.05
0.0475
0.0451
0.0429
Explanation / Answer
28. P(All girls)
= 0.8 * 0.8 * 0.8
= 0.512
Option D is correct.
31. P(Winning on the third ticket)
= P(Loosing in first two tickets) * P(Winning on third)
= (0.95)2 * (0.05)
= 0.0451
Option C is correct.
32. P(Winning on the second ticket)
= P(Loosing in first ticket) * P(Winning in second)
= (0.95) * (0.05)
= 0.0475
Option B is correct.