(1) Create a data frame with column 1: 1,2,3,4,5,6 and column 2: a,b,a,b,a,b. Let the two column names to be col1 and col2.

(2) Select only rows with value a in column 2 using logical vector.

(3) mtcars is a built-in data set: select the rows of the mtcars data such that mpg is greater than 15 and smaller than 30, and assign these rows to a tibble data frame.

IN R STUDIO