Steemit mind TEST!!

3 steemians walk into a hotel
they ask at the counter how much it is to stay in the hotel
they are told it is 0.0030 bitcoin for a room
the steemians decide that to save money they will share a room
each of the steemians give 0.0010 bitcoin to the person at the counter and make their way to their room

Later that day the manager comes in and asks the person on the counter why he hadn't given the steemians a steemian discount
"don't you know for fellow steemians a room is only 0.0025 bitcoin?"
the manager calls over the bell boy and gives him 0.0005 bitcoin to refund to the 3 steemians..
on the way to the steemians' room the bellboy decides to pocket 0.0002 bitcoin for himself out of the 0.0005 he was given
he knocks on the door of the room
the 3 steemians answer..(all at once)
"hello steemians i am the bell boy and i have been instructed to give you some of your money back as you have been given a steemian discount by the manager"
the bell boy gives 0.0001 bitcoin to each of the steemians keeping back the 0.0002 bitcoin he had already pocketed..
"thanks young man" says one of the steemians
all 3 of the steemians are very happy with the steemian discount..
"we shall have to come here again" one of the steemians declares

so with the discount the steemians have now only paid 0.0009 bitcoin each for the room instead of the 0.0010 they'd initially paid making their total cost 0.0027 bitcoin and remember the bell boy took 0.0002 bitcoin for himself...
add both sums together and you get 0.0029 bitcoin...

where has the missing 0.0001 bitcoin gone?

(i will be impressed if anyone gets this ;)