Matrix multiplication (%*%) in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to multiply two matrices A and B.

R Programming

result <- A [1] B

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

A%*%

B*

C+

D%%

Attempts:

3 left

💡 Hint

Common Mistakes

Using * which does element-wise multiplication instead of matrix multiplication.

Using + which adds matrices instead of multiplying.

In R, the operator %*% is used for matrix multiplication.

2fill in blank

medium

Complete the code to multiply matrix M by vector v using matrix multiplication.

R Programming

result <- M [1] v

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

A%*%

B*

C/

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using * which does element-wise multiplication and gives wrong results.

Using + which adds instead of multiplies.

The %*% operator multiplies matrices and vectors properly in R.

3fill in blank

hard

Fix the error in the code to correctly multiply matrices X and Y.

R Programming

Z <- X [1] Y

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

A+

B*

C%%

D%*%

Attempts:

3 left

💡 Hint

Common Mistakes

Using * which multiplies elements individually, not matrices.

Using + which adds matrices instead of multiplying.

Matrix multiplication in R requires the %*% operator, not the element-wise *.

4fill in blank

hard

Fill both blanks to create a matrix multiplication of A and B, then add matrix C.

R Programming

result <- (A [1] B) [2] C

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

A%*%

B+

C*

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using * instead of %*% for matrix multiplication.

Using - instead of + for addition.

First multiply A and B with %*%, then add C with +.

5fill in blank

hard

Fill all three blanks to multiply matrices X and Y, then subtract Z, and finally multiply by scalar s.

R Programming

final <- ((X [1] Y) [2] Z) [3] s

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

A%*%

B-

C*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using * instead of %*% for matrix multiplication.

Using + instead of - for subtraction.

Using %*% to multiply by scalar instead of *.

Multiply X and Y with %*%, subtract Z with -, then multiply by scalar s with *.