VERY IMPORTANT QUESTION FOR THE EXAM, PAY ATTENTION
1) To find the number of days between order date and shipping date, we will make use of a calculated field:

In the data pane, click on the dropdown arrow, and choose create calculated field.
Let's name this calculated field "ShippingDelay" (you can name it anything you want :) )
2) Use the DATEDIFF() function, and pass it the arguments as follows:

'day' depicts that we want to calculate the number of DAYS between the two dates. The first argument is 'start_date' which is the ORDER_DATE (day the order was placed), the second argument is 'end_date', which is the SHIP_DATE (date the order was shipped). So by subtracting as follows: SHIP_DATE - ORDER_DATE, we can find the delay in shipping.
Click OK.
3) You should now have a new measure as follows:

4) Phew! The hard part is done! Now let's filter by Market to include only LATAM:

5) Drag Country to the view, and the new calculated field 'ShippingDelay' to SIZE on the Marks Shelf as follows:
*You can also click on Show Text Labels to be sure that you're choosing the Largest value*

Clearly, Mexico has the highest Shipping Delay!

This is a tricky question. We are talking about story POINTS, and not entire stories in the question.
To create a story, lets say I have a blank story with 1 dashboard and 1 worksheet.
I can simply drag the dashboard into the view to create a new story point.

Now, if I try to adjust the worksheet beside it in this same view, I cannot. See below:

The only option available is to replace the existing view. Therefore, the answer is NO since they both cannot be added.
Read more about stories in Tableau: https://help.tableau.com/current/pro/desktop/en-us/story_create.htm

Explanation
According to Tableau's order of operations, the Extract filter is right at the top of the hierarchy. The data filtered in the Extract is then passed on to what we see in the Data Pane. See below:

Very important question for the exam and appears quite a lot too.
The correct answer is - By dragging another dimension to Color on the Marks card.
Chart, bar chart Description automatically generated

This is what the question says we have already created. Now to convert this into a Stacked bar chart, we will drop another dimension on Color in the Marks card.
Chart, bar chart Description automatically generated

The rest won't create stacked bar charts, and hence are incorrect choices. The best way to answer such questions on the real exam is to quickly do what the options say and see if they satisfy the requirements in the question.

From the official documentation:
The default view that you first see in the Data Source page canvas is the logical layer of the data source. You combine data in the logical layer using relationships (or noodles).