Hello, got this from an old GMAT Paper Test (Disclosed Ed, Code 25). I'm a little unsure as to how I should model the solution to the problem. I think it's an RTD problem. I tried to make an RTD chart, but I got a bit lost, especially since the rates are expressed in terms of room/time. Any equation/model/chart of the variables and solution would be greatly appreciated.

Image attached

The figure above represents the floor plan of an art gallery that has a lobby and 18 rooms. If Lisa goes from the lobby into room A at the same time that Paul goes from lobby into room R, and each goes through all of the rooms in succession, entering by one door and exiting by the other, which room will they be in at the same time?

(1) Lisa spends 2x minutes in each room and Paul spends 3x minutes in each room.

(2) Lisa spends 10 minutes less time in each room than Paul.

## DS: Art Gallery

##### This topic has expert replies

You get respective rates.

In 6x minutes, lisa covers 3 rooms while other guys covers 2 rooms..

lets say x=1 and then calculate....they will meet in room K.

2) is insufficient... try different values and u will get different rooms,depending on what value u chose.

whats the official answer?

Mac