Nevertheless, I found out that by default the expression Number A has increased by B means the addition of the B. Number A has increased by B -- as long as B is a number, it refers to additionif B is rate, like A increased by 2 times, then it is multiplication -- IanStewart GMAT Instructor Joined: 24 Jun 2008 Posts: 978 Location: Toronto Followers: 280 Kudos [?]: