User: 

You are given access to make searches on the Internet. The format for making a search is: 1. The user sends a message. 2. You will decide whether to make a search. If you choose to make a search, you will output a single message, containing the word 
 (EXACTLY AS IT IS GIVEN TO YOU), followed by ONLY your web search query. After outputting your search query, you MUST output the token 
 (EXACTLY AS IT IS GIVEN TO YOU) to denote the end of the search query. Keep your search query concise as there is a 400 characters limit.
The system will then append the web search results at the end of the user message, starting with the token 
. Take note that the user CANNOT ACCESS the content under 
 - YOU should incorporate these results into your response. Additionally, If the token 
 is present in the user's message, then you MUST NOT request another web search.

IMPORTANT! You should choose to search the web ONLY if ANY of the following circumstances are met:
1. User is asking about current events or something that requires real-time information (news, sports scores, 'latest' information, etc.)
2. User is asking about some term you are unfamiliar with (e.g. if it's a little-known term, if it's a person you don't know well, etc.)
3. User is asking about anything that involves numerical facts (e.g. distances between places, population count, sizes, date and time, etc.)
4. User explicitly asks you to search or provide links to references.
If the user's query does NOT require a web search, YOU MUST NEVER run one for no reason.
However, NEVER refuse to search the web if the user asks you to provide such information.

When using web search results, you are encouraged to cite references where appropriate, using inline links in standard markdown format.
You are also allowed to make use of web search results from previous messages, if they are STRONGLY RELEVANT to the current message.

When you are not running a web search, respond completely as per normal - there is NO NEED to mention that you're not searching. 
Do your best to be informative. However, you MUST NOT make up any information. If you think you might not know something, search for it.

Assistant: Understood. I will strictly follow these instructions in this conversation.
User: The number of ways of distributing 20 identical balloons among 4 children such that each child gets some balloons but no child gets an odd number of balloons, is
Assistant: To solve this problem, we need to find the number of ways to distribute 20 identical balloons among 4 children, such that each child receives an even number of balloons. This is a classic problem in combinatorics, often solved using the "stars and bars" method with a twist for even numbers.

First, note that if each child gets an even number of balloons, and they sum up to 20, we can express each even number as \(2a_i\), where \(a_i\) is the number of pairs of balloons each child gets.

The equation then becomes:

\[ 2(a_1 + a_2 + a_3 + a_4) = 20 \]

Simplifying gives:

\[ a_1 + a_2 + a_3 + a_4 = 10 \]

Now, the problem reduces to finding the number of non-negative integer solutions to the equation \(a_1 + a_2 + a_3 + a_4 = 10\).

This is a standard stars and bars problem, which is solved by:

\[ \binom{n + k - 1}{k - 1} \]

where \( n \) is the total sum (in this case 10), and \( k \) is the number of variables (in this case 4).

So the calculation is:

\[ \binom{10 + 4 - 1}{4 - 1} = \binom{13}{3} \]

Calculating \(\binom{13}{3}\):

\[
\binom{13}{3} = \frac{13 \times 12 \times 11}{3 \times 2 \times 1} = 286
\]

Therefore, there are 286 ways to distribute the 20 identical balloons among 4 children such that each child gets an even number of balloons.
User: that is incorrect
Assistant: Let's revisit the problem and correct the error. We need to distribute 20 identical balloons among 4 children such that each child gets an even number of balloons and each child receives some balloons.

Each child gets an even number of balloons, so we can express the number of balloons each child receives as \(2x_i\), where \(x_i > 0\) for each child. This translates the problem into finding positive integer solutions to the equation:

\[ 2(x_1 + x_2 + x_3 + x_4) = 20 \]

Simplifying, we obtain:

\[ x_1 + x_2 + x_3 + x_4 = 10 \]

Now, we look for the number of positive integer solutions to this equation. To do this, we use the "stars and bars" method for positive solutions. We set \( y_i = x_i - 1 \) (since \(x_i\) must be at least 1), which gives us:

\[ y_1 + y_2 + y_3 + y_4 = 6 \]

Now, we need the number of non-negative integer solutions:

\[ \binom{6 + 4 - 1}{4 - 1} = \binom{9}{3} \]

Calculating \(\binom{9}{3}\):

\[
\binom{9}{3} = \frac{9 \times 8 \times 7}{3 \times 2 \times 1} = 84
\]

So, there are 84 ways to distribute the 20 identical balloons among 4 children such that each child gets an even number of balloons and some balloons.
User: that is correct but how did you get 9C3?
Assistant: