An organizer wants to seat 600 students for a presentation on good health. He decides on the number of rows to be used and realizes that the number of chairs per row will be ten less than twice the number of rows. How many rows and how many chairs per row will he be using?

Luigi is the first person to finish a 5k race and is standing 13 feet beyond the finish line. another runner, mario, is still running the race and has approximately 24 feet before he reaches the finish line. what is the distance between mario and luigi? explain through words, numbers or pictures how you found the answer.