First consider that the shopping items are ranked in price from 1 (lowest) to 6 (highest). So a combination could be 351426, with the 3rd most expensive item in the Mailbox, and so on until the highest priced item (6) is in the Attic. When selected, the 'Mailbox' and 'Attic' are single items, while the two middle 'Floors' are two items each. The total possible combinations of choices are therefore: * Mailbox: 6 possibilities * 1st Floor: 10 possibilities (in math, this is: 5 Items, Choose 2) * 2nd Floor: 3 possibilities (3 Items, Choose 2) * Attic: 1 possibility