5 stars and a thank you

If you have 12 feet of string and you cut it into equal length of 5 inches each how much string will be left

Kerion has a beaded necklace business. she can make 12 necklaces is 2 hours. how long will it take her to make 9 necklaces?

Xy x xy if a and b are positive integers such that a*b=9 and b*a=72 what is the value of a/b