Amandahertzog

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 #1
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We can use the complement principle to solve this problem. That is, we can first count the number of ways that no flavor of ice cream is selected by exactly two children, and then subtract that from the total number of possible choices.

There are three flavors of ice cream, and each child can choose any of the three flavors. So the total number of possible choices is 3^6.

Now, let's count the number of ways that no flavor of ice cream is selected by exactly two children. There are two cases to consider:

Case 1: No flavor of ice cream is selected by more than one child. In this case, the first child can choose any of the three flavors. The second child can choose any of the two remaining flavors. The third child can choose any of the two remaining flavors. The fourth child can choose any of the two remaining flavors. The fifth child can choose any of the two remaining flavors. The sixth child can choose the last remaining flavor. So there are 32222*1 = 48 ways to make choices in this case.

Case 2: One flavor of ice cream is selected by exactly two children, and the other two flavors are each selected by one child. In this case, there are three ways to choose which flavor will be selected by exactly two children. Once that is chosen, there are 4 ways to choose which two children will select that flavor. Then, the remaining two flavors can be assigned to the remaining four children in 22 = 4 ways. So there are 34*4 = 48 ways to make choices in this case as well.

Therefore, the total number of ways to make choices so that some flavor of ice cream is selected by exactly two children is 3^6 - 48 - 48 = 585. Answer: \boxed{585}. MI Bridges App

Mar 27, 2023
 #1
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To find the total number of possible sequences of 12 coin tosses, we can use the multiplication rule, which states that if there are k independent events with n1 possible outcomes for the first event, n2 possible outcomes for the second event, and so on, then the total number of possible outcomes is n1 * n2 * ... * nk.

For each of the 12 tosses, there are two possible outcomes, heads or tails. Therefore, the total number of possible sequences of 12 coin tosses is 2^12 = 4096.

To find the number of sequences with at least k heads, we can use the complement rule, which states that the probability of an event happening is 1 minus the probability of the event not happening. In this case, the probability of getting at least k heads is equal to 1 minus the probability of getting less than k heads.

Let's consider the case where k = 1, i.e., we want to find the number of sequences with at least one head. The number of sequences with no heads is just 1 (i.e., all tails), so the number of sequences with at least one head is 4096 - 1 = 4095.

For the case where k = 2, we want to find the number of sequences with at least two heads. The number of sequences with no heads or one head is 1 + 12 = 13, so the number of sequences with at least two heads is 4096 - 13 = 4083.

Using this approach, we can find the number of sequences with at least 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 heads, by subtracting the number of sequences with fewer than k heads from the total number of sequences.

Alternatively, we can use the binomial distribution formula to calculate the number of sequences with at least k heads:

Number of sequences with at least k heads = sum from i=k to i=12 of (12 choose i) = (12 choose k) + (12 choose k+1) + ... + (12 choose 12)

where (n choose k) represents the binomial coefficient, which gives the number of ways to choose k items from a set of n items. MI Bridges

Mar 25, 2023
 #2
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To solve this problem, we can use the principle of inclusion-exclusion.

First, we find the total number of ways to distribute the balls without any restrictions. This is equivalent to finding the number of ways to put 10 indistinguishable balls into 8 distinguishable boxes, which is given by the formula:

$${10 + 8 - 1 \choose 8 - 1} = {17 \choose 7} = 19,448$$

Next, we find the number of ways to distribute the balls such that no box is empty. This is equivalent to finding the number of ways to put 10 indistinguishable balls into 8 distinguishable boxes such that each box has at least one ball. We can think of this as a stars and bars problem with the additional constraint that each box must have at least one star (ball). Using the stars and bars formula, we get:

$${10 - 1 \choose 8 - 1} = {9 \choose 7} = 36$$

However, we are interested in the number of ways such that at least one box is empty. To find this, we use the principle of inclusion-exclusion. Let A be the event that box 1 is empty, B be the event that box 2 is empty, and so on up to H for box 8. Then the number of ways to distribute the balls such that at least one box is empty is given by:

$$\sum_{i=1}^{8} (-1)^{i-1} \binom{8}{i} {10 - i - 1 \choose 8 - 1}$$

where the $(-1)^{i-1}$ term comes from the alternating signs in the inclusion-exclusion formula.

Using this formula, we get:

$$\sum_{i=1}^{8} (-1)^{i-1} \binom{8}{i} {10 - i - 1 \choose 8 - 1} = 19,448 - 36\binom{8}{1} + \binom{8}{2} {1 \choose 7} - \binom{8}{3} {2 \choose 7} + \cdots + (-1)^{8-1} \binom{8}{8} {2 \choose 7}$$

Simplifying this expression gives:

$$19,448 - 8\times36 + 28\times0 - 56\times0 + 70\times0 - 56\times0 + 28\times0 - 8\times0 + 1\times0 = 19,064$$

Therefore, the number of ways to distribute 10 indistinguishable balls among 8 distinguishable boxes, if at least one of the boxes must be empty, is 19,064. Subaru Net

Mar 21, 2023
 #1
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0

To solve this problem, we can use the angle bisector theorem and the properties of cyclic quadrilaterals.

First, let's draw a diagram:B / \ / \ / \ / \ / \ / \ A-------------C

Since AB is a diameter of the circle, angle ACB is a right angle (90 degrees).

Let AM be the angle bisector of angle ACB. Then, by the angle bisector theorem, we have:

AC AM -- = ----- BC BM

Substituting the given values, we get:

8 AM -- = --- 4 BM

Simplifying, we get:

AM = 2BM

Now, let's draw the line CM and label the point where it intersects the circle as D:B / \ / \ / D \ / \ / \ / \ A-------------C | | M

Since AM is twice BM, we can let BM = x and AM = 2x. Then, using the Pythagorean theorem in triangle ABC, we have:

AC^2 + BC^2 = AB^2 8^2 + 4^2 = AB^2 AB = 2sqrt(5)

Since AD and BD are radii of the circle, we have AD = BD = AB/2 = sqrt(5).

Now, let's use the properties of cyclic quadrilaterals to find the length of CD. Since angle CMB is an inscribed angle that intercepts arc CD, we have:

angle CMB = 1/2 * arc CD

Also, angle CAM and CBM are equal because they are opposite angles of an isosceles triangle. Therefore, angle AMC = 180 - 2CAM = 180 - 2CBM. Since angle AMC is an inscribed angle that intercepts arc CD, we have:

angle AMC = 1/2 * arc CD

Adding these two equations, we get:angle CMB + angle AMC = arc CD 1/2 * arc CD + 1/2 * arc CD = arc CD arc CD = angle ACB = 90 degrees

Therefore, CD is a diameter of the circle, and CM is the radius. Since CM = CD/2, we have:CM = AB/2 - AC/2 = (2sqrt(5))/2 - 8/2 = sqrt(5) - 4

Therefore, CM = sqrt(5) - 4. My AARP Medicare

Mar 7, 2023