Q. What can be done when more people than you can cater for accept an invitation? We are giving a two-hour 21st-birthday drinks party for our daughter. Our Chelsea cottage will hold a maximum of 70 but, adhering to the immutable law of party-giving, which is that a third of those you invite will be unable to come, I advised my daughter to send out a hundred invitations in the expectation that only 70 would accept.