Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

A professional gambler has won 40% of his 25 poker games for [#permalink]
03 Jun 2012, 10:37

00:00

A

B

C

D

E

Difficulty:

25% (medium)

Question Stats:

78% (02:27) correct
22% (02:00) wrong based on 60 sessions

A professional gambler has won 40% of his 25 poker games for the week so far. If, all of a sudden, his luck changes and he begins winning 80% of the time, how many more games must he play to end up winning 60% of all his games for the week?

Re: Percentage problem [#permalink]
03 Jun 2012, 16:57

BDSunDevil wrote:

He needs to win 60% of all the game, i. e. 60% of 25 = 15 He already won 40% of 25 = 10 games. He needs to win 5 more. However his chance is 80%. That is, for every 5 games he play, he win 4. Therefore, he must play (5*5/4)=6.2= 7 more games to win total 15 games. What is the OA?

Re: Percentage problem [#permalink]
03 Jun 2012, 22:54

1

This post received KUDOS

Sorry for the last post.

If he plays X more games, the equation becomes: games with 40% chance + Games with 80% chance = Total games with 60% chance .40*25 + .80*X=.60*(25+X) Solving for X = 25

Re: A professional gambler has won 40% of his 25 poker games for [#permalink]
03 Jun 2012, 23:41

2

This post received KUDOS

Expert's post

farukqmul wrote:

A professional gambler has won 40% of his 25 poker games for the week so far. If, all of a sudden, his luck changes and he began winning 80% of the time, how many more games must he play to end up winning 60% of all his games for the week?

explanation is given in MGMAT book but I didn't understand it...Can anyone please explain?

Re: A professional gambler has won 40% of his 25 poker games for [#permalink]
04 Jun 2012, 01:52

2

This post received KUDOS

Expert's post

farukqmul wrote:

A professional gambler has won 40% of his 25 poker games for the week so far. If, all of a sudden, his luck changes and he began winning 80% of the time, how many more games must he play to end up winning 60% of all his games for the week?

explanation is given in MGMAT book but I didn't understand it...Can anyone please explain?

'The number of games out of which he won 40% games' is equal to 'the number of games out of which he must win 80% of the games'. He won 40% of the games out of 25 games. So he must win 80% of the games out of another 25 games. _________________

Re: Percentage problem [#permalink]
04 Jun 2012, 06:31

davidandcompany wrote:

farukqmul wrote:

A professional gambler has won 40% of his 25 poker games for the week so far.If,all of a sudden,his luck changes and he began winning 80% of the time,how many more games must he play to end up winning 60% of all his games for the week?

explanation is given in MGMAT book but I didn't understand it...Can anyone please explain?

Let x = number of games more must he play

0.4(25) + 0.8x = 0.6(25+x) <--- You should be able to grasp this idea.

Re: Percentage problem [#permalink]
04 Jun 2012, 06:33

Expert's post

farukqmul wrote:

davidandcompany wrote:

farukqmul wrote:

A professional gambler has won 40% of his 25 poker games for the week so far.If,all of a sudden,his luck changes and he began winning 80% of the time,how many more games must he play to end up winning 60% of all his games for the week?

explanation is given in MGMAT book but I didn't understand it...Can anyone please explain?

Let x = number of games more must he play

0.4(25) + 0.8x = 0.6(25+x) <--- You should be able to grasp this idea.