Data Sufficiency

GMAT Paper Tests



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 the 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 does.

OA A

Statement 1
Lisa spends two minutes per room while Paul uses three minutes per room
At the end of 6 minutes, Lisa would have checked 3 rooms While Paul will just be finishing 2 rooms.

Rooms Checked by Lisa
$$BCD\left(6\min utes\right)$$
$$EFG\left(6\min utes\right)$$
$$HIJ\left(6\min utes\right)$$
$$K\left(1\min utes\right)$$

Rooms checked by Paul
$$QP\left(6\min utes\right)$$
$$ON\left(6\min utes\right)$$
$$ML\left(6\min utes\right)$$
$$K\left(1\min utes\right)$$

Lisa and Paul will meet in the room k after 19 minutes,
Statement 1 is INSUFFICIENT.

Statement 2
Lisa spends 10 minutes less time in each room than Paul does.

This shows that Lisa is moving at a faster pace than Paul but we don't know the the exact time that each of them spent in a room.
Hence statement 2 is INSUFFICIENT.
Only statement 1 is SUFFICIENT.
$$answer\ is\ Option\ A$$