Math Riddles

Question: what does 1+1=.

Question: In a house of Kardak's family each brother have a sisters as double as their brothers and each sister have brothers as same as their sister. How many brothers and sisters in Kardak's family ?

Question: There are 6 sisters. Each sister has 1 brother. How many brothers are in the sisters' family?

Question: It takes ten men ten hours to build a certain wall. How long does it take five men to build the same wall?

Question: Tom wants to send Sally an expensive ring through the mail because they live thousands of miles apart. The only problem is that everything sent through the mail is stolen unless there is a lock put on it. Both Tom and Sally have plenty of locks and keys but they don't have any of the same locks or keys.

How can Tom send Sally the ring without it getting stolen?