If she maintains her average amount of movies bought every week, then she will buy 20 DVDs in 10 weeks. Explanation: she buys 4 every week, so if we want to find out how many are in 10 weeks, we must multiply two until we get to 10 ( five weeks ) then multiply that buy her average of movies. And that is how we get the answer of 20 DVDs! ( her at least I did )
