Two boats leave a port on a river at the same time, traveling in opposite directions. each is traveling 22mph. how long will it take them to be 110 miles apart?

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