Every room in a building has at least two windows and a maximum of 4 windows. There are 122 windows total. If 5 rooms have 4 windows and 8 rooms have 3 windows, how many rooms in the building have 2 windows? Let's be accurate as possible.
Since 5 rooms have 4 windows, this accounts for 20 windows because 4 * 5 = 20 windows. Since 8 rooms have 3 windows, this accounts for 24 windows because 8 * 3 = 24 windows. There are 78 windows left over because 122 - 20 - 24 = 78. Therefore, there are 39 rooms with 2 windows because 78 / 2 = 39.
The answer: 39.