So I'm gonna rent an apartment with some friends this summer. I'm trying to get the figures right. Somehow my logic is failing.

see, the apartment costs 490 euro/week. that makes 70 euro/day.

We're five people who's gonna live there. three of us are staying 12 nights, two stays 11 nights.
So - 70/5 equals 14. 14€ /day for everyone right?
14*11 = 154.
14*12 = 168.

168*3 = 504.
154*2 = 308.

504+308 = 812. Now, see 12 days should equal 840€. So now I just remebered that the last day should be divided by three. 70/3 = 23,33333...
It was such a long time since I studied math. *sigh*.
Everyone should just pay 154 each - then the three of us pay an extra 23,333...
154+23,3 = 177,3.

177,3*3 = 519,9
154*2 = 308

519,9+308 = 827,9.... I'm afraid I might be confusing people with my disoriented thoughts... I'm thinking very weird somewhere along these lines. Well, it should equal up to 840.

Can somebody please help me?