You put $2,200 into an investment yielding 6% simple annual interest; you left the money in for two years. How much simple interest do you get at the end of those two years?

Problem number 26 of the rhind papyrus says: find a quantity such that when it is added to of itself the result is a 15. the modern day equation that models this problem is x + x = 15. what is the solution to the equation? x = 10 x = 12 x = 15 x = 30