I am planning a party next weekend. I have invited 100 people. Last week I took advantage of an offer at my local supermarket where I was able to get 10% off the total price of party food if I spent more than $75.Ipaid$108 and I estimate that the food that I bought will be enough for 60 people. I've now had replies to the invitations and I know that there will be 80 people at the party. This afternoon I will buy the remaining food that I need.