**1. What are the advantages of R?**

**Answer:** The advantages are:-

1. It is used for managing and manipulating of data.

2. No license restrictions

3. Free and open source software.

4. Graphical capabilities of R are good.

5. Runs on many Operating systems and also run on 32 & 64 bit processors etc.

**2. Which is the function used for adding datasets in R?**

**Answer: **For adding two datasets rbind() function is used but the column of two datasets must be same.

**Syntax: rbind(x1,x2……) where x1,x2: vector, matrix, data frames.**

**3. How you can produce co-relations and covariances?**

**Answer:** Cor-relations is produced by cor() and covariances is produced by cov() function.

**4. What is difference between matrix and dataframes?**

**Answer:** Matrix can contain only similar type of data, whereas Dataframe can contain different type of data

**5. What is difference between lapply and sapply?**

**Answer: **lapply is used to show the output in the form of list whereas sapply is used to show the output in the form of vector or data frame

**6. What is the difference between seq(4) and seq_along(4)?**

**Answer: **Seq(4) means vector from 1 to 4 (c(1,2,3,4)) whereas seq_along(4) means a vector of the length(4) or 1(c(1)).

**7. How can you start the R commander GUI. Explain?**

**Answer: **rcmdr command is used to start the R commander GUI.

**8. What is the memory limit of R?**

**Answer: ** In 32 bit system memory limit is 3Gb but most versions limited to 2Gb and in 64 bit system memory limit is 8Tb.

**9. How many data structures R has?**

**Answer:** There are 5 data structure in R i.e. vector, matrix, array which are of homogenous type and other two are list and data frame which are heterogeneous.

**10. Explain how data is aggregated in R.**

**Answer:** There are two methods that is collapsing data by using one or more BY variable and other is aggregate() function in which BY variable should be in list.