College

A friend of mine is giving a dinner party. His current wine supply includes 8 bottles of zinfandel, 10 of merlot, and 12 of cabernet (he only drinks red wine), all from different wineries.

a. If he wants to serve 3 bottles of zinfandel and serving order is important, how many ways are there to do this?

b. If 6 bottles of wine are to be randomly selected from the 30 for serving, how many ways are there to do this?

c. If 6 bottles are randomly selected, how many ways are there to obtain two bottles of each variety?

d. If 6 bottles are randomly selected, what is the probability that this results in two bottles of each variety being chosen?

e. If 6 bottles are randomly selected, what is the probability that all of them are the same variety?

Answer :

Answer:

a) 336

b) 593775

c) 83160

d) P=0.14

e) P=0.0019

Step-by-step explanation:

We have wine supply includes 8 bottles of zinfandel, 10 of merlot, and 12 of cabernet.

a) If he wants to serve 3 bottles of zinfandel and serving order is important. We get:

C=8·7·6=336

b) {30}_C_{6}=\frac{30!}{6!(30-6)!}

{30}_C_{6}=593775

c) {8}_C_{2} · {10}_C_{2} · {12}_C_{2}=

=\frac{8!}{2!(8-2)!} · \frac{10!}{2!(10-2)!} · \frac{12!}{2!(12-2)!}

=28 · 45 · 66

=83160

d) We calculate the number of possible combinations:

{30}_C_{6}=593775

We calculate the number of favorable combinations:

{8}_C_{2} · {10}_C_{2} · {12}_C_{2}=83160

The probability that this results in two bottles of each variety being is

P=83160/593775

P=0.14

e) We calculate the number of possible combinations:

{30}_C_{6}=593775

We calculate the number of favorable combinations:

{8}_C_{6} + {10}_C_{6} + {12}_C_{6}= 28+210+924=1162

The probability is

P=1162/593775

P=0.0019

Final answer:

A friend has several options for serving wine at a dinner party, including 336 ways to serve 3 bottles of zinfandel in order, 593,775 ways to randomly select 6 bottles from 30, and 90 ways to select 2 bottles of each variety among 6 bottles. The probabilities for the specific selections are 0.01515% and 0.11707%, respectively.

Explanation:

Your friend has various options for serving wine at a dinner party:

If he wants to serve 3 bottles of zinfandel and the serving order is important, he has Permutation options: 8P3 = 8! / (8-3)! = 8 x 7 x 6 = 336 ways to do this.

If 6 bottles of wine are randomly selected from the total of 30, he has Combination options: 30C6 = 30! / (6! (30-6)!) = 593,775 ways to do this.

If 6 bottles are randomly selected and the goal is to have two bottles of each variety, we use the formula for multinomial coefficients: (6!)/(2!2!2!) = 90 ways to achieve this.

The probability of selecting exactly two bottles of each variety is the number of favorable outcomes divided by the total number of outcomes: (90/593,775) = 0.0001515, or about 0.01515%.

The probability that all 6 randomly selected bottles are of the same variety can be calculated by adding the probabilities for each variety: (8C6 + 10C6 + 12C6) / 30C6 = (28 + 210 + 924) / 593,775 = 0.0011707, or about 0.11707%.