From 1 to 100

[Kel]

if its $2 she kept then that means the men paid $28, but the mens only paid $9 each. 3 times $9 is $27? Wheres the 28th dollar?

The men paid £10 each, they got £1 back, that leaves £2

3 X 9 is 27 but they never paid that, they paid £10 each.

they got a $1 back out of the $10 they each paid which means $1 - $10 = $9.

They pay £9 each so £27 altogether, the hotel got £25 and she got £2. 25+2=27 it's just a mind fuck. They paid £10 each and got a quid back 30-3 is 27, as is 25+2.