These type of questions can occur in both quant or DI depending on length and difficulty of the questions.
I have a presentation made about Venn Diagrams, but I am a little under the weather and am unable to record narration right now.
The slides are pretty self explanatory so I don’t think anyone will have a problem in understanding them.
Here you have the presentation in .ppt format. It is only 88.5 Kb.
Here you go a screenshot of the presentation.
Hope you like the tutorial!
Exercise:
The exercise for similar problems such as the ones solved in the presentation are here.
The file is in .doc format and is of 37 Kb.
Hope you like the post!
Do come back for more!! 
