OK this is dumb beyond belief, but I have been offered a cheap deal on something that seems too good to be true. Basically for each pack of 200 I pay £53.80, but I want to know how much 20 costs. To do this I assumed all I had to do was divide 200 by 53.80 to get the price for one of these items and then multiply this by 20 to get the cost of 20. But this works out at a stupidly cheap price of about 73 pence for 20. I know this is dumb and it can't possibly be right, as I have never seen these items sold so cheaply. What am I doing wrong?