R Markdown document creation in R Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple R Markdown chunk

What will be the output shown in the knitted document for this R Markdown chunk?

R Programming

```{r}
x <- 5
x * 2
```

A Error: object 'x' not found

B x * 2

C 5

D 10

💡 Hint

The chunk runs R code and shows the result of the last expression.

The variable x is assigned 5, then multiplied by 2. The output is the value 10.

🧠 Conceptual

intermediate

Purpose of YAML header in R Markdown

What is the main purpose of the YAML header at the top of an R Markdown document?

A To write R code that runs before the document

B To specify document metadata and output format

C To add comments inside the document

D To create tables and figures automatically

💡 Hint

YAML header is enclosed by --- lines and sets options for the whole document.

The YAML header defines metadata like title, author, date, and output format such as HTML or PDF.

🔧 Debug

advanced

Identify the error in this R Markdown chunk

What error will this R Markdown chunk produce when knitted?

R Programming

```{r}
summary(data.frame(a = 1:3, b = c('x', 'y')))
```

A Error: arguments imply differing number of rows: 3, 2

B No error, outputs summary of data frame

C Error: object 'data' not found

D Error: unexpected symbol in 'summary(data.frame(a = 1:3, b = c('

💡 Hint

Check if the vectors used to create the data frame have the same length.

The vector 'a' has length 3 but 'b' has length 2, so data.frame() fails with a row number mismatch error.

📝 Syntax

advanced

Correct syntax for including inline R code in R Markdown

Which option shows the correct way to include inline R code that prints the value of variable n in R Markdown text?

A {{n}}

B ${n}$

C `r n`

D <%= n %>

💡 Hint

Inline R code is enclosed in backticks with r before the expression.

Inline R code uses backticks and the letter r like `r expression` to evaluate and insert the result.

🚀 Application

expert

Number of output files generated by knitting an R Markdown document to HTML

If you knit an R Markdown document named report.Rmd to HTML, how many files are typically created in the output folder?

A One HTML file and one folder with supporting files

B One HTML file named report.html

C Only the original Rmd file is updated

D Multiple HTML files, one per code chunk

💡 Hint

Consider how images and dependencies are stored when knitting to HTML.

Knitting to HTML usually creates one HTML file plus a folder with images, CSS, and JavaScript needed for the document.