## 1. What is the correct way to assign a value to a variable in R?

### Answer:

### Explanation:

In R, the most common way to assign a value to a variable is using the '<-' operator. The '=' operator can also be used, but '<-' is preferred in R programming for clarity and tradition.

## 2. Which of these is a valid variable name in R?

### Answer:

### Explanation:

Variable names in R can start with a period ('.') followed by a character, but they cannot start with a number, have dashes, or only consist of special characters.

## 3. How can you check the data type of a variable in R?

### Answer:

### Explanation:

In R, 'typeof()' is used to determine the data type of a variable, such as integer, double, character, etc.

## 4. Which of the following is not a basic data type in R?

### Answer:

### Explanation:

List is a data structure in R, not a basic data type. The basic data types include numeric, character, and integer.

## 5. How can you create a vector in R?

### Answer:

### Explanation:

In R, vectors are created using the 'c()' function, which combines values into a vector.

## 6. What will be the output of the following code? x <- "5"; as.numeric(x)

### Answer:

### Explanation:

The 'as.numeric()' function converts the character string "5" into the numeric value 5.

## 7. Which of the following is used to create a sequence of numbers in R?

### Answer:

### Explanation:

The 'seq()' function is used in R to create a sequence of numbers with specified start, end, and step values.

## 8. What will be the result of the expression 'is.na(NA)' in R?

### Answer:

### Explanation:

'is.na()' checks if a value is 'NA' (missing value) in R, and returns TRUE if it is.

## 9. How do you comment a single line in R script?

### Answer:

### Explanation:

In R, a single line comment is initiated with the '#' symbol.

## 10. Which function is used to install packages in R?

### Answer:

### Explanation:

The 'install.packages()' function is used to install new packages in R, while 'library()' or 'require()' are used to load them into the current session.

## 11. What does the R function 'rm()' do?

### Answer:

### Explanation:

The 'rm()' function is used to remove specified objects from the memory (workspace) in R.

## 12. Which of these is the correct way to access the third element of a vector 'vec' in R?

### Answer:

### Explanation:

In R, elements of a vector are accessed using square brackets, with the index of the element inside the brackets.

## 13. How is a missing value represented in R?

### Answer:

### Explanation:

In R, 'NA' is used to represent missing or unavailable data.

## 14. Which function can be used to read a CSV file in R?

### Answer:

### Explanation:

The 'read.csv()' function is widely used for reading CSV (Comma Separated Values) files into R.

## 15. What is the outcome of the expression 'sqrt(-1)' in R?

### Answer:

### Explanation:

In R, taking the square root of a negative number results in 'NaN', which stands for 'Not a Number'.