Can you work this out?

you and 2 mates buy a dinghy for 30 quid. You all put a tenner to it and leave happily. The manager of the shop returns and tells the sales girl that he reduced it to 25 quid. he gives her 5 pound coins and sends her after you. She realises that there are only three of you..She tells you it had been reduced, hands each of you 1 pound and pockets the other 2. You have now paid 9 pounds each for the dinghy. Which is 27 pound. and she pocketed 2 pound. Which makes 29 pounds. Where did the other pound go?