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## Picking apples

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amit.trivedi@ymail.com GMAT Destroyer!
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Wed May 02, 2012 11:45 pm
The two equations:

42y + (42-a) X 1.5y = 180-----------------(i)

42y + (42-b) X 1.5y = 240-----------------(ii)

and also considering that b = a + 10, we get

then solving both the equations, we get

I am getting y = -4 which is not possible.

And so the two simultaneous equations are not giving the values

That is why the answer is E.

If the simultaneous equations are giving the answers then we could still have figure out as to what are the number of bushels harvested, whether less than 42 or greater than 42.

Hence the correct answer comes out to be E and not C...

Thanks...

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amit.trivedi@ymail.com GMAT Destroyer!
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Thu May 03, 2012 12:13 am
Another reason why as to DanaJ is correct is the following table:

(1) a1/a2 = b1/b2 = c1/c2 (the same line) will not give the solution

(2) a1/a2 = b1/b2 (not equal to) c1/c2 (parallel lines) will not give the solution

(3) a1/a2 (not equal to) b1/b2 (not equal to) c1/c2 (intersecting lines) will give unique solutions

The striking thing is that the above 2 equations given in the question does not match any of the above criteria.

Also in the above two equations, a1/a2 (not equal to) b1/b2 (not equal to) c1/c2

then too the two equations are not able to give the correct answer...

y cannot be negative.

That is why the answer is E and also that many experts say that whenever you see a DS question,

do not solve the question completely, but I say that always solve till the end.

Most of the times in such cases the confusion is between the answer choices C and E.

i.e even here I thought that the answer is C but it turned out to be E, only after solving the entire two equations...

Hope this helps...

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jerryzheng Just gettin' started!
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Tue May 15, 2012 12:46 am
IMO E
There are two scenarios that can fit both two premises
1. Y=4 Day1 45 brushels
2. Y=6 Day1 30 brushels

karthikgmat Really wants to Beat The GMAT!
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Tue May 15, 2012 8:12 pm
immaculatesahai wrote:

Will not be able to successfully isolate 2 equations and 2 unknowns.
Hey 3 unknowns here? Did you mistype?

thevenus Just gettin' started!
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Sun Aug 26, 2012 3:21 am
I did a blunder , i thought D could be the answer without considering "y"...

mparakala Rising GMAT Star
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Thu Dec 20, 2012 12:26 pm
E

There is no information about "y". there is no information about how many he picked a day

rajeshsinghgmat Really wants to Beat The GMAT!
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Wed Feb 13, 2013 5:30 pm

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Tommy Wallach GMAT Instructor
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Wed Feb 13, 2013 6:17 pm
Hey Guys,

Very important rule here.

Quote:
i see how your explanation gets to answer E. But when preparing for the GMAT, we learn that if you have 2 variables, and 2 equations, you can find the answer. What is the rule here as to why we cannot find the 2 variables?
On the GMAT, this is NOT a rule. I am very nervous if you read this anywhere. That's a rule from middle school algebra. On the GMAT, generally they will subvert rule, in any one of a million ways they know how to subvert it. For example:

What's x?

1) 2x + 4y = 16
2) 4x = 32 - 8y

Here, we have two equations and two variables...or do we?! Actually, it's the same equation, so the answer would be E. Be very careful with that old chestnut rule about equations/variables on the GMAT!

-t

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ritzzzr Rising GMAT Star
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Thu Feb 14, 2013 5:03 am
WE GET DIFFERENT VALUES DO NOT GEET UNIQUE VALUE
SO E IS THE SOLUTION

chapelhillmom Just gettin' started!
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Tue Feb 19, 2013 9:35 am
If he must pick some apples each day at the higher price (1.5 y), the problem can be solved this way:

equation 1:
180=42y+1.5y(x-42) where x is the total busells picked on day 1
180= 42y+1.5xy-63y
180=1.5xy-21y
1.5xy=180+21y

equation 2:
240=42y+1.5y(x+10-42)
240=42y+1.5y(x-32)
240=42y+1.5xy-48y
240=1.5xy-6y
1.5xy=240+6y

Putting the two expressions for 1.5xy together, we get:
180+21y=240+6y
15y=60
y=4
total bushels on day 1 =44 and on day 2 =54

Deepthi Subbu Really wants to Beat The GMAT!
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Sun Apr 21, 2013 12:34 am
Hi,

Let the no of bushels harvested yest be by and today be bt. When both combined, the eqns are the following. Let T be the total bushels harvested -

y(42) + (by-42)(1.5y)=180
y(42) + (by+10-42)(1.5y) = 240

Solving both , I get y= - 4. With a negative value, the value of by cannot be calculated.

Hence E

mishra.santanu Just gettin' started!
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Sun Apr 21, 2013 5:32 am
I have solved two equation to get y value as 4.
42y+(42+x)1.5y = 180 ............... (1)
42y+(42+x)1.5y+15y = 240 ........... (2)

When I have replaced y = 4 ir satisfied both statement 1 and 2.

1st day 42 * 4 + 2 * 6 = 180
2nd day 180 + 10 * 6 = 240

So I will go with C.

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