Yes nepalean is right. That $2 tips is already added in $9 share because room rent is $25. ie. 25/3 = $8.33, which $0.67 less than $9. Now, if you multiply $0.67 by 3, you would approx. get $2, which is the tips that the bell boy already got. There is no need to $2, that's just the flaw in the question itself. Hope bhate bro has understood now. If not, go to high school. LOL!!