There is a lot of dust in Susie's house. It takes her 2 hours to vacuum the whole house. She can vacuum each room in 20 minutes. How many rooms does she have in her house? Let's be accurate as possible.
Susie spends 2 * 60 = 120 minutes vacuuming. Since she can vacuum each room in 20 minutes, she has 120 / 20 = 6 rooms in her house.
The answer: 6.