Bunuel
Team X won 40 basketball games. What percent of its basketball games did Team X win?
(1) Team X played the same number of basketball games as Team Y.
(2) Team Y won 45 games, representing 2.5 percent of the basketball games it played.
Given: Team X won 40 basketball games.
Asked: What percent of its basketball games did Team X win?
(1) Team X played the same number of basketball games as Team Y.
Let us assume Games team X played = Games team Y played = x
% game Team X won = 40 / 2x = (2000/x)%
Since x is unknown
NOT SUFFICIENT
(2) Team Y won 45 games, representing 2.5 percent of the basketball games it played.
Team Y played = 45 / 2.5% = 4500/2.5 = 1800 games
% games Team X won = (4000 / Games Team X played + Games Team Y played)%
There is no information about games Team X played
NOT SUFFICIENT
(1) + (2)
(1) Team X played the same number of basketball games as Team Y.
Let us assume Games team X played = Games team Y played = x
% game Team X won = 40 / 2x = (2000/x)%
(2) Team Y won 45 games, representing 2.5 percent of the basketball games it played.
Team Y played = 45 / 2.5% = 4500/2.5 = 1800 games
% games Team X won = 4000 / (1800 + 1800) % = 1 1/9 %
SUFFICIENT
IMO C