Please produce the answers in R, also please don't use other sites to answer this question.

1.2Use the following script, we can generate a 3X4 matrix tmp<-matrix(rnorm(12), 3, 4).

1. Answer the following questions.
2. (1) Compute the sum of the first and third column. (The sum of the 1st column and then the sum of the 3rd column both independently)
3. (2) Compute the product of the first and third row.
4. (3) Show the dimension of the matrix.
5. (4) Use 'cat' function to output elements in the first row that are larger than 0.5.