1) If it takes twenty minutes to hard-boil one goose egg, how long will it take to hard-boil four goose eggs?

20 minutes, 4 eggs can be boiled at the same time.

2) Some months have 31 days. How many have 28?
 

   .....Twelve (12). All of them have at least 28 days.    

3) Can a man in California  marry his widow's sister?

     ....No. He must be dead if it is his widow.
    
4) Take the number 30, divide it by 1/2, and then add 10.
     What do you get?
 

   .....  Seventy (70).  Thirty (30) divided by 1/2 is 60.
    
5) A doctor gives you three pills and tells you to take one every half
     an hour.   How long will the pills last?
 

   ......One hour. If you take the first pill at 1:00, the second at
     1:30, and the third at 2:00, the pills have run out and only one hour
     has passed.
    
6) A farmer has 17 sheep. All but 9 of them die. How many sheep are
     left?
 

   .....  Nine (9). Like I said, all BUT nine die.
    
   7) A butcher in the market is 5' 10 tall. What does he weigh?
  

  .....  Meat ... that is self-explanatory.