if i pay £280 for a room for 12 days. then someone joins for 6 days and pays an excess £60, how much do they owe me?
Assuming that there is only the 2 of you and you share the cost 'fairly' then
Total cost = 280+60=340
person days = 1*6+2*6=18
$340/18
Total cost for me = 340/18*12 =$226.67
Total cost for other person = 340/18*6 =$113.33
But other person has already paid $60
So they owe 113.33-60 = $53.33
Assuming that there is only the 2 of you and you share the cost 'fairly' then
Total cost = 280+60=340
person days = 1*6+2*6=18
$340/18
Total cost for me = 340/18*12 =$226.67
Total cost for other person = 340/18*6 =$113.33
But other person has already paid $60
So they owe 113.33-60 = $53.33