Practice Exercise $8\mathrm{.}1\mathrm{.}4$ to $6$

Consider the following array

$8\mathrm{.}1\mathrm{.}4)$ Using single index notation, use the find$$function to find the index numbers of the elements in the array that contain values greater than $10$ and less than $40$ and call the results index.

$8\mathrm{.}1\mathrm{.}5)$ Find the row and column numbers $($sometimes called subscripts$)$ of the elements in the array that contain values greater than $10$ and less than $40,$ using the find$$function$...$ and call the results rows$$and cols.

$8\mathrm{.}1\mathrm{.}6)$ Determine the values$$in the array that are greater than $10$ and less than $40,$ using either the results from part a or part b$.$ Call your answer x$\_$gt$\_$lt