A couple's wedding reception had 180 people. The bride and groom had each invited 20 couples from their side of the family. The remaining guests were friends. How many friends attended the reception?
Thoughts? Step-by-step reasoning:
From the bride's side, 20 couples * 2 guests / couple = 40 guests attended. From the groom's side, 20 couples * 2 guests / couple = 40 guests attended. Therefore 180 guests - (40 guests + 40 guests) = 100 friends attended the reception.
Thus, the answer is 100.