The price of milk has been steadily increasing 5% per year. if the cost of a gallon is now $3.89: what will it cost in 10 years? what did it cost 5 years ago?

You’re ordering more thread for blue jeans co. you usually purchase from ted’s threads, which sells 12 thread spools for $27. you recently received a notice from wade's wares that says you can buy thread from them for $2.30 each for the first 2 dozen and $2 a spool thereafter. you need to order 5 dozen spools. what percentage can you save by going with wade’s wares?