1. How many numbers of columns are there in the given output?

>dim(Grades)

[1] 80 2

(a) 80 (b) 2

(c) NA (d) 0

2. What will be the output of the following code?

>head(dataset, n=5)

(a) returns first 5 observations (b) returns last 5 observations

(c) returns first 6 default observations (d) returns last 6 default observations

3. What will be the output of the following code:

>tail(dataset, n=-55), where there are total 70 observations?

(a) returns first 15 observations

(b) returns last 15 observations

(c) returns first 55 default observations

(d) returns last 55 default observations

4. What will be the output of the following code? is.invalid(c(0,Inf,0))

(a) FALSE TRUE TRUE (b) FALSE FALSE FALSE

(c) FALSE TRUE FALSE (d) TRUE TRUE TRUE

5. Which function is used to open a data editor?

(a) edit() (b) str()

(c) summary() (d) open()

6. Which is not an invalid value in R?

(a) -inf (b) NA

(c) 0 (d) NaN

7. Which one of the following is used to drop missing values?

(a) na.rm=TRUE (b) na.rm=FALSE

(c) na.rm=0 (d) na.rm=NA

8. Which parameter is used to mention the width of each bar in a histogram?

(a) width (b) col

(c) breadth (d) xlab