To find out how many invitations each person has to take to the post office, we first need to determine the total number of people mailing the invitations. There are Susan, Benjamin, and three members of the bridal party, making a total of:
1 (Susan) + 1 (Benjamin) + 3 (bridal party members) = 5 people
Next, we divide the total number of invitations by the number of people:
225 invitations รท 5 people = 45 invitations per person
Therefore, each person has to take 45 invitations to the post office. The correct response is:
45