Question 9353
start with the definition: 


1 foot = 12 inches
--> 2 feet = 12*2
--> 3 feet = 12*3
--> 4 feet = 12*4
so
--> x feet = 12*x


that is your answer.


For anything like this, you can always start from first principles, look at numerical examples, find the pattern and then create the "general" version.


jon.