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A professional gambler has won 40% of his 25 poker games for [#permalink]

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03 Jun 2012, 11:37

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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?

A professional gambler has won 40% of his 25 poker games for [#permalink]

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03 Jun 2012, 23:54

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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

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?

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.
_________________

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.

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: A professional gambler has won 40% of his 25 poker games for [#permalink]

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17 Apr 2016, 08:56

ok, the question says that 40% of the games 25 games are won => 10 games. then the question says that 60% of all the games are won => 60% ( x + 25) it tells you that 80% of the remaining games are won => 80% (x)

the equation is => 40%(25) + 80%(x) = 60% (x+25) => 10+ .80x = .6x + 15 => .2x = 10 => x = 25.

Re: A professional gambler has won 40% of his 25 poker games for [#permalink]

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07 Jun 2017, 20:53

Bunuel 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?

40% of 25 games plus 80% of x games should equal to 60% of total number of games, which is (25+x) --> 0.4*25+0.8*x=0.6*(25+x) --> x=25.

Hope it's clear.

Bunuel - this is the same formula I derived- do we need to necessarily plug in and test each of the answer choices? Or can we just simplify the equation?

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?

A. 20 B. 25 C. 30 D. 35 E. 40

We are given that a poker player has won 0.4 x 25 = 10 poker games. If he starts winning 80% of his games, we need to determine how many more games must be played to have a winning percentage of 60% for the week. We can let x = the number of additional games played and we have:

(10 + 0.8x)/(25 + x) = 60/100

(10 + 0.8x)/(25 + x) = 3/5

5(10 + 0.8x) = 3(25 + x)

50 + 4x = 75 + 3x

x = 25

Answer: B
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