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08 Oct 2012, 02:53
1
12
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Difficulty:

55% (hard)

Question Stats:

66% (01:39) correct 34% (01:33) wrong based on 1384 sessions

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Max has $125 consisting of bills each worth either$5 or $20. How many bills worth$5 does Max have?

(1) Max has fewer than 5 bills worth $5 each. (2) Max has more than 5 bills worth$20 each.

Practice Questions
Question: 59
Page: 280
Difficulty: 600

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08 Oct 2012, 05:07
6
2
SOURH7WK wrote:
Let x be $5 bill & y be$20 bill, 5x+20y =125, Find x?
ST1: Sufficient: x<5, Therefore x can be 0,1,2,3,4. Here only x=1 satisfy the given equation and for all other value y will not be an integer value.
ST2: Sufficient: y>5, y=6,7,8... Now for y =7 the total value exceeds 125. Therefore Y must be 6. And so x will be 1.

A suggestion: always divide an equation by the GCD of the coefficients, it becomes easier to handle. In this case, 5x + 20y = 125, divide through by 5 and get:
x + 4y = 25. Smaller numbers, positive integers...isn't it easier to see the solutions?

(1): Another approach would be to look at 25 as being a M4+1 (remainder 1 when divided by 4). 4y is divisible by 4, therefore x must leave a remainder of 1 when divided by 4. Since x is less than 5, the only possibility is x = 1. Just to practice divisibility properties...:O)
(2): y > 5, then 4y > 20. Because 4*7 = 28 > 25, the only possible value for y is 6, and x must be 1.

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08 Oct 2012, 03:20
imo d...each alone is sufficient
let the number of bills of 5$b x and bills for 20$ be y
now we have only two situations where 5x+20y=125
either
x=1 and y=6 --> (true wen we use statement 1)
or
x=5 and y=5 --> (true wen we use statement 2)

using any of the above two statements we can find out the answer.

statement1:
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10 Jan 2014, 08:45
1
Bunuel wrote:
Max has $125 consisting of bills each worth either$5 or $20. How many bills worth$5 does Max have?

(1) Max has fewer than 5 bills worth $5 each. (2) Max has more than 5 bills worth$20 each.

Practice Questions
Question: 59
Page: 280
Difficulty: 600

Basically, the stem gives us: 5*x + 20*y = 125, and asks us what x is.

1) tells us that x < 5, so we try to maximize for 20 to control what possible values x can take. For y = 5 we have x = 5 and for y = 6 we have x = 1, no other combinations in that range are possible between X and Y. And since 1) makes it impossible for x = 5, x must be = 1.. So 1 is sufficient.

2) tells us that y > 5, so again we test if there are different possible values for y. For y = 6 we have x = 1.. And y can't actually be a higher value than 6 because then we break the restriction of 125 USD.. So clearly, y = 6 and x = 1, so 2 is sufficient.

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Re: Max has $125 consisting of bills each worth either$5 or $20 [#permalink] ### Show Tags 13 Dec 2017, 21:31 Hi All, We're told that Max has$125 consisting of bills worth $5 or$20 each. We're asked for the number of $5 bills that Max has. Based on the 'restrictions' in this question, there are only a handful of possible ways to get to$125. As such, I'm going to list them out first (before we deal with the two Facts):

$125: Six 20s and one 5 Five 20s and five 5s Four 20s and nine 5s Three 20s and thirteen 5s Two 20s and seventeen 5s One 20 and twenty-one 5s Zero 20s and twenty-five 5s 1) Max has fewer than 5 bills worth$5 each.

With this Fact, there's only one possible option: Six 20s and one 5.
Fact 1 is SUFFICIENT

2) Max has more than 5 bills worth $20 each. With this Fact, there's only one possible option: Six 20s and one 5. Fact 2 is SUFFICIENT Final Answer: GMAT assassins aren't born, they're made, Rich _________________ 760+: Learn What GMAT Assassins Do to Score at the Highest Levels Contact Rich at: Rich.C@empowergmat.com # Rich Cohen Co-Founder & GMAT Assassin Special Offer: Save$75 + GMAT Club Tests Free
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Max has $125 consisting of bills each worth either$5 or $20 [#permalink] ### Show Tags 29 Dec 2017, 02:40 Bunuel, niks18, amanvermagmat Quote: Let $$x$$ be the # of 5$ bills and $$y$$ the # of 20$bills --> $$5x+20y=125$$ --> $$x=?$$ Any particular reason for not simplifying this to x+4y=25 before analyzing statements? Also we can use plugging approach since we know multiples of 5 and 20 and Sum = 125 but it took me few extra sec to plug in values from 1 to 4 for x. (For constant value of y=1) _________________ It's the journey that brings us happiness not the destination. Max has$125 consisting of bills each worth either $5 or$20 &nbs [#permalink] 29 Dec 2017, 02:40
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