Before play-offs, a certain team had won 80 percent of its games. Afte

Question

Before play-offs, a certain team had won 80 percent of its games. After play-offs, what percent of all its games had the team won?

(1) The team competed in 4 play-off games.
(2) The team won all of its play-off games.

Bunuel · Answer

The question asks about the percent of the total games that the team won.

For (1)+(2) we have that the team won 80% of games played before play-offs and 100% of 4 games played after. Now, without knowing how many games were played before play-offs we cannot answer the question.

For example if before play-offs the team played 5 games then it won 8 out of 9 games (4 before and 4 after) but if before play-offs the team played 10 games then it won 12 out of 14 games (8 before and 4 after).

Answer: E.

AD2GMAT · Answer

I couldn't understand the question, and option B. Could anyone please explain?

Bunuel · Answer

The team played certain number of games before play-offs plus certain number of games in play-offs. We want to know what percent of all its games had the team won. (2) says that the team won all of its play-off games. Check complete solution here: https://gmatclub.com/forum/before-play- ... l#p1071527 Hope it helps.

Nikkb · Answer

Before play-offs, a certain team had won 80 percent of its games. After play-offs, what percent of all its games had the team won?
Let no. of games before playoff = x
Game wons = 80% of x = 0.8x

(1) The team competed in 4 play-off games.
so total no. of games = x+4. But here we don't know how many games team won. So we cannot calculate % of won games. So Not sufficient

(2) The team won all of its play-off games.
Team won all games. But we don't know how many games are being played. SO we don't know final total number of games. Not sufficient

1+2
Now we know team played 4 more games and won all
So total number of games = x+4
Total games won = 0.8x+4

% of games won = (0.8x +4) /(x+4) *100

Here we cannot solve equation as we don't know x and nothing cancels out. So Not sufficient.

Answer: E

AD2GMAT · Answer

Thanks a lot for the clarification  Bunuel  - please accept my Kudos also.

BrentGMATPrepNow · Answer

Given : Before play-offs, a certain team had won 80 percent of its games

Target question :    After play-offs, what percent of all its games had the team won?

Strategy: It's sometimes useful to ask ourselves why the target question is impossible to answer without any additional information . 
In this case, we can't answer the target question because we don't know the total number of games played  before  the playoffs, and we don't know the total number of games played  during  the playoffs.
When I scan the two statements, I see that neither of them provide information about the total number of games played  before  the playoffs.
This leads me to believe that the statements combined are still not sufficient.
So, I’m going to head straight to……

Statements 1 and 2 combined    
There are several scenarios that satisfy BOTH statements. Here are two: 
 Case a : The team played 5 games before the playoffs, which means they won 4 of those 5 games (i.e., 80%). Then the team won all 4 of its playoff games. In total, the team played 9 games and won 8 of them. So, the answer to the target question is   the team won about 89% of its games

Case b : The team played 20 games before the playoffs, which means they won 16 of those 20 games (i.e., 80%). Then the team won all 4 of its playoff games. In total, the team played 24 games and won 20 of them. So, the answer to the target question is   the team won about 83% of its games

Since we can’t answer the  target question  with certainty, the combined statements are NOT SUFFICIENT

Answer: E

punwani7 · Answer

If the team won all of its games after playoffs, can't we just take that as 100 percent of the games won and choose answer B? Can someone help me out?

siddhantvarma · Answer

We're asked " After play-offs, what percent of  all  its games had the team won?" B gives you that 100% of the games were won after play offs, we need to find the overall percent of all games won, which would include (games won before playoffs + games won after playoffs)/total games played

siddhantvarma · Answer

KarishmaB  can we solve this question using the concept of weighted average?
Before playoffs: 80%, number of games : unknown
To find overall percentage of games won, we need: 
- Percentage of games won before playoffs (given, 80%)
- Total number of games played before playoffs (unknown)
- Percentage of games won after playoffs (unknown)
- Total number of games played after playoffs (unknown)

(1) The team competed in 4 play-off games.
This gives us the Total number of games played after playoffs, but two quanities are still unknown => Inusfficient

(2) The team won all of its play-off games.
This gives us the Percentage of games won after playoffs (100%), but two quanities still unkown => Insufficient

Combining the two, Total number of games played before playoffs is still unknown => (E)

KarishmaB · Answer

Yes you can and you got it exactly right.

80% wins before playoffs and 100% wins at playoffs. For overall win percentage, we need the number of games played in each. We know 4 playoff games were played but how many were played before play offs, we don't know. Hence not sufficient together.

Answer (E)

Before play-offs, a certain team had won 80 percent of its games. Afte

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