Math Riddles

Question: someone came into my shop and stole 100 dollars from the register without my knowledge. the person came back 5 minutes later with the same 100 dollars and bought 70 dollars in items and i gave him back 30 dollars change. How much did i lose?

Question: 1 11 21 1211 111221 312211 13112221 1113213211 what comes next?

Question: can you make an equation by using only the no.-4,4,4,4 whose answer will be 20.

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: When i was 4 my sister was half my age. Now I am 100. How old is my sister now?