STORE 1 Buy one get one free is the same as 2 for the price of one, so it would cost 45×37=$1665 for 90 1-drawer cabinets, or 90 drawers, equivalent to 30 3-drawer cabinets.
STORE 2 For $100 you get 5 drawers (1 3-drawer cabinet and 1 2-drawer cabinet), so to get 90 drawers, you need 90/5=18 sets of two cabinets at a cost of $1800.
STORE 3 You need 30 3-drawer cabinets costing 30×55=$1650.
STORE 4 90 drawers cost 90×19.20=$1728.
The best value for money is Store 3. In order of least to most expensive for the same number of drawers in total, we have: Store 3, 1, 4, 2.
(The unit price of the drawers in the same order are $18.33, $18.50, $19.20, $20. In many countries stores are required by law to state the unit price of goods, so that shoppers can compare prices of different sized packages without having to do the arithmetic. Worth noting this when you go shopping.)
