>1) A paper-eating insect plans to make a tunnel in a 3-volume encyclopedia (the volumes are on the shelf, in the library, and placed in the usual order). The tunnel is to start on page 1 of volume 1, and end on the last page of volume 3. How many days will this take, supposing the insect requires 1 day for each cover, and 3 days for the pages of one volume? Note: after trying this out in your head, or with pencil and paper, it helps to actually take a look at real books.

Wouldn't the bug be dead if he started between the cover and the first page?

>2) Is it legal for a man to marry his widow's sister?

Probably in some cultures, but it might be difficult.

>3) A patient goes to the doctor. His complaint: "Every time I drink coffee, I have a severe pain in my right eye". What should the doctor recommend the patient?

Take the spoon out.