Respuesta :
1. Exactly three 1 s?
[tex]$\left(\begin{array}{c}12 \\3\end{array}\right)=220$[/tex]
2. At most three[tex]$1 \mathrm{~s}$[/tex] ?
[tex]$\left(\begin{array}{c}12 \\0\end{array}\right)+\left(\begin{array}{c}12 \\1\end{array}\right)+\left(\begin{array}{c}12 \\2\end{array}\right)+\left(\begin{array}{c}12 \\3\end{array}\right)=1+12+66+220=299 \text {. }$[/tex]
3. At least three 1 s?
Take a shortcut by using the previous answer:[tex]$2^{12}-66-12-1=4017$[/tex]
4. An equal number of[tex]$0 \mathrm{~s}$[/tex] and [tex]$1 \mathrm{~s}$[/tex] ?
[tex]$\left(\begin{array}{c}12 \\6\end{array}\right)=924$[/tex]
What is strings ?
The C programming language includes a set of functions executing operations on strings in its standard library. Different operations, such as copying, concatenation, tokenization, and searching are supported.
In C programming, a string exists as a sequence of characters terminated with a null character \0. For example char c[] = "c string"; When the compiler discovers a sequence of characters enclosed in the double quotation marks, it appends a null character \0 at the end by default. The C language does not have a distinctive "String" data type, the way some other languages such as C++ and Java do. Instead, C stores strings of characters as arrays of chars, completed by a null byte.
1. Exactly three 1 s?
[tex]$\left(\begin{array}{c}12 \\3\end{array}\right)=220$[/tex]
2. At most three[tex]$1 \mathrm{~s}$[/tex] ?
[tex]$\left(\begin{array}{c}12 \\0\end{array}\right)+\left(\begin{array}{c}12 \\1\end{array}\right)+\left(\begin{array}{c}12 \\2\end{array}\right)+\left(\begin{array}{c}12 \\3\end{array}\right)=1+12+66+220=299 \text {. }$[/tex]
3. At least three 1 s?
Take a shortcut by using the previous answer:[tex]$2^{12}-66-12-1=4017$[/tex]
4. An equal number of[tex]$0 \mathrm{~s}$[/tex] and [tex]$1 \mathrm{~s}$[/tex] ?
[tex]$\left(\begin{array}{c}12 \\6\end{array}\right)=924$[/tex]
To learn more about strings refer to:
https://brainly.com/question/27251062
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