Ei liked to play tennis. One day she didn't have anyone to play with, so she took her racket and
tennis ball and began to hit the ball against the backboard. She hit it at the backboard, the ball
bounced off the backboard and came back to her, and she hit it again, and so on. She started out
40 feet from the backboard. But she didn't hit the ball hard enough—the bounce came back only
90% as far, so she had to run up to hit it again. Again, she didn't hit it hard enough, and it again only
came back 90% as far as she had hit it. This continued for two more hits, each time the ball coming
back 90% as far. Finally on the fifth hit she hit it really hard and it came back five times as far as she
had hit it, going way over her head and hitting the fence. She got frustrated and picked up her ball
and went home. How far was the distance from the backboard to the fence? What was the total
horizontal distance that the tennis ball traveled?