Arithmetic operators in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add two numbers and print the result.

R Programming

result <- 5 [1] 3
print(result)

Drag options to blanks, or click blank then click option'

A+

B-

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using - instead of + will subtract instead of add.

Using * or / will multiply or divide, not add.

The + operator adds two numbers in R.

2fill in blank

medium

Complete the code to multiply two numbers and print the result.

R Programming

result <- 7 [1] 4
print(result)

Drag options to blanks, or click blank then click option'

A-

B+

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using + or - will add or subtract instead of multiply.

Using / will divide instead of multiply.

The * operator multiplies two numbers in R.

3fill in blank

hard

Fix the error in the code to correctly divide two numbers and print the result.

R Programming

result <- 10 [1] 2
print(result)

Drag options to blanks, or click blank then click option'

A/

B-

C+

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using * multiplies instead of divides.

Using + or - adds or subtracts instead of divides.

The / operator divides the first number by the second in R.

4fill in blank

hard

Fill both blanks to create a named vector where each number is squared only if it is greater than 3.

R Programming

[1] <- 1:5; squares <- setNames([2]^2[[1] > 3], [1][[1] > 3])

Drag options to blanks, or click blank then click option'

Ax

Bi

Cj

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names for the name and the value causes errors.

Using a variable not defined in the loop causes errors.

Using the same variable i for the name and the value allows squaring numbers greater than 3.

5fill in blank

hard

Fill all three blanks to create a vector of numbers from 1 to 5, then subtract 2 from each number and print the result.

R Programming

numbers <- [1](1, 2, 3, 4, 5)
result <- numbers [2] [3]
print(result)

Drag options to blanks, or click blank then click option'

Ac

B-

C2

Dseq

Attempts:

3 left

💡 Hint

Common Mistakes

Using seq instead of c changes the vector creation.

Using + instead of - adds instead of subtracts.

Using a wrong number instead of 2 changes the result.

c() creates a vector, - subtracts, and 2 is the number to subtract.

Practice

1. Which of the following operators in R is used for multiplication?

easy

A. -

B. +

C. *

D. /

Solution

1. Step 1: Recall basic arithmetic operators in R

   In R, * is used for multiplication, + for addition, - for subtraction, and / for division.

2. Step 2: Identify the multiplication operator

   The operator * multiplies two numbers.

3. Final Answer:

   * -> Option C

4. Quick Check:

   Multiplication operator = * [OK]

Hint: Remember * means multiply in math and R [OK]

Common Mistakes:

• Confusing * with + or -
• Using / for multiplication
• Using ^ for multiplication

2. Which of the following is the correct syntax to calculate the remainder of 10 divided by 3 in R?

easy

A. 10 %% 3

B. 10 /% 3

C. 10 %/% 3

D. 10 % 3

Solution

1. Step 1: Understand remainder operator in R

   In R, the operator %% gives the remainder after division.

2. Step 2: Identify correct syntax for remainder

   10 %% 3 calculates remainder of 10 divided by 3, which is 1.

3. Final Answer:

   10 %% 3 -> Option A

4. Quick Check:

   Remainder operator = %% [OK]

Hint: Use %% for remainder, not % or /% [OK]

Common Mistakes:

• Using single % instead of %%
• Confusing integer division %/% with remainder %%
• Typing operators incorrectly like /%

3. What is the output of the following R code?

result <- 5 + 3 * 2
print(result)

medium

A. 16

B. 11

C. 10

D. 13

Solution

1. Step 1: Apply operator precedence in R

   Multiplication (*) has higher priority than addition (+), so 3 * 2 = 6 is calculated first.

2. Step 2: Calculate the expression

   Then add 5 + 6 = 11.

3. Final Answer:

   11 -> Option B

4. Quick Check:

   5 + (3 * 2) = 11 [OK]

Hint: Multiply before adding due to operator precedence [OK]

Common Mistakes:

• Adding before multiplying
• Ignoring operator precedence
• Calculating 5 + 3 first

4. Identify the error in this R code snippet:

value <- 10 %/ 3
print(value)

medium

A. Syntax error due to incorrect operator

B. Runs correctly and prints 3

C. Runs correctly and prints 1

D. Runtime error due to division by zero

Solution

1. Step 1: Check the operator used

   The operator %/ is not valid in R. Integer division uses %/%.

2. Step 2: Identify the error type

   Using %/ causes a syntax error because R does not recognize it.

3. Final Answer:

   Syntax error due to incorrect operator -> Option A

4. Quick Check:

   Integer division operator is %/% not %/ [OK]

Hint: Use %/% for integer division, not %/ [OK]

Common Mistakes:

• Typing %/ instead of %/%
• Confusing remainder %% with integer division
• Expecting output despite syntax error

5. You want to calculate the integer division and remainder of 17 divided by 4 in R. Which code correctly assigns both results to variables int_div and rem?

hard

A. int_div <- 17 %/ 4rem <- 17 %% 4

B. int_div <- 17 %% 4rem <- 17 %/% 4

C. int_div <- 17 / 4rem <- 17 % 4

D. int_div <- 17 %/% 4rem <- 17 %% 4

Solution

1. Step 1: Recall operators for integer division and remainder

   Integer division uses %/% and remainder uses %% in R.

2. Step 2: Match operators to variables

   int_div <- 17 %/% 4 correctly assigns integer division result (4).
   rem <- 17 %% 4 correctly assigns remainder (1).

3. Final Answer:

   int_div <- 17 %/% 4; rem <- 17 %% 4 -> Option D

4. Quick Check:

   Integer division %/% and remainder %% used correctly [OK]

Hint: Use %/% for int division, %% for remainder [OK]

Common Mistakes:

• Swapping operators for int division and remainder
• Using invalid operator %/
• Using / instead of %/% for integer division