Problem Solving (PS) | Re: Marcia has 2 liters (L) of a 60% concentrated solution of phosphoric a

May 31, 2019, 1:00 am

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This question can be solved using the percentage values provided. Since this is a ‘Could be’ type of question, a better idea would be to use the alligation diagram to prove a statement right, once (wherever feasible)

Let’s take the case of statement I. Let’s draw the alligation diagram for thesevalues:

Attachment:

31st May 2019 - Reply 4.JPG [ 18.47 KiB | Viewed 19 times ]

The concentration of the mixture is less than 50%. It means statement I is a possible value. Therefore, options B and C can be eliminated.
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Problem Solving (PS) | Re: The function f is defined as f(x,y) = xy for positive numbers x and y.

May 31, 2019, 1:00 am

≫ Next: Data Sufficiency (DS) | Quick Sell Outlet sold a total of 40 televisions, each of

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Could anyone please explain me the solution for this

Posted from my mobile device

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Data Sufficiency (DS) | Quick Sell Outlet sold a total of 40 televisions, each of

May 31, 2019, 1:00 am

≫ Next: Data Sufficiency (DS) | Re: What is the sum of the digits of the positive integer n

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bulletpoint wrote:

Quick Sell Outlet sold a total of 40 televisions, each of which was either a Model P television or a Model Q television. Each Model P television sold for $p and each Model Q sold for $q. The average (arithmetic mean) selling price of the 40 televisions was $141. How many of the 40 televisions were Model P televisions?

Given: n = 40, Avg = 141, $p, $q, P Tvs, Q Tvs.
This is a weighted average question, we can use a number line to visualize as perVeritasKarishma method:

1) the Model P televisions sold
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Data Sufficiency (DS) | Re: What is the sum of the digits of the positive integer n

May 31, 2019, 1:00 am

≫ Next: Problem Solving (PS) | Re: Mary, John, and Karen ate lunch together. Karen’s meal cost 50 percent

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Bunuel wrote:

samark wrote:

What is the sum of the digits of the positive integer n where n < 99?

1) n is divisible by the square of the prime number y.

2) y4 is a two-digit odd integer.

What is the sum of the digits of the positive integer n where n < 99?

(1) n is divisible by the square of the prime number y --> clearly insufficient, as no info about y.

2) y^4 is a two-digit odd integer --> also insufficient, as no info about n, but from this statement we know that if y is an integer then y=3
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Problem Solving (PS) | Re: Mary, John, and Karen ate lunch together. Karen’s meal cost 50 percent

May 31, 2019, 1:00 am

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Data Sufficiency (DS) | Is integer n a natural number? 1) n^2-8 is sequence of a natural numbe

May 31, 2019, 1:00 am

≫ Next: Problem Solving (PS) | 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%

≪ Previous: Problem Solving (PS) | Re: Mary, John, and Karen ate lunch together. Karen’s meal cost 50 percent

Is integer $n$ a natural number?
1) $n^2-8$ is sequence of a natural number
2) $n^3-7$ is cube of a natural number

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Problem Solving (PS) | 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%

May 31, 2019, 1:00 am

≫ Next: Data Sufficiency (DS) | Re: If sequences S has 240 terms, what is the 239th term of S?

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1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60% alcohol. If x > y, how many integer values can x take?

A. 10
B. 20
C. 35
D. 13
E. 30

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Data Sufficiency (DS) | Re: If sequences S has 240 terms, what is the 239th term of S?

May 31, 2019, 1:00 am

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If sequences S has 240 terms, what is the 239th term of S?
In order to find the 239th term, we need:
1. the value of one of the terms in sequence S
2. the common change between sequentialterms.

1) Each term of S after the first term is 4 less than the preceding term
This gives us the common change (difference = -4), but we don't know the value of any terms. Not sufficient.

2) The 239th term of S is 952 less than the first term This tells us is that$a_1 - 952 = a_{239}$
So we have the range between
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Data Sufficiency (DS) | Re: 100 Hardest and easiest questions for DS as of April 2019

May 31, 2019, 1:00 am

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Data Sufficiency (DS) | Re: What is the distance between City A and City C ?

May 31, 2019, 1:00 am

≫ Next: Data Sufficiency (DS) | Re: What is the perimeter of triangle ABC ? (1) AB = 16 inches (2) ABC is

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Solution

Steps 1 & 2: Understand Question and Draw Inferences

We are giventhat:

•Three cities – A, B, and C.
We need to findthe:

•Distance between city A and C.
S we do not have much information to infer from, let us now analyse the individual statements.

Step 3: Analyse Statement 1
“The distance between City A and City B is 75 kilometres.”

•From this statement, we cannot find the distance between city A and C.
Thus, statement 1 is not sufficient to answer the question.

Step 4: Analyse Statement 2
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Data Sufficiency (DS) | Re: What is the perimeter of triangle ABC ? (1) AB = 16 inches (2) ABC is

May 31, 2019, 1:00 am

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≪ Previous: Data Sufficiency (DS) | Re: What is the distance between City A and City C ?

Solution

Steps 1 & 2: Understand Question and Draw Inferences

We aregiven:

•A triangle ABC.
We need to find itsperimeter.

•So, we need the length of all the sides of the triangle.

As we do not have any more relevant information, let us now analyse the statements.

Step 3: Analyse Statement 1
“AB = 16 inches”

From this information, we cannot find the answer to the question as we are not given the lengths of other two sides.
Thus, statement 1 is not sufficient to answer the
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Data Sufficiency (DS) | Re: If a and b are integers, and b > 0, does (a - 1)/(b + 1) = a/b ?

May 31, 2019, 1:00 am

≫ Next: Problem Solving (PS) | Re: v, w, x, y, and z are five positive integers for which v≤w≤x≤y≤z. If t

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Solution

Steps 1 & 2: Understand Question and Draw Inferences

In this question, we aregiven

We need to determine whether (a-1)/(b+1) = a/b
Simplifying the given expression above, weget

•ab – b = ab + a
Or, a = -b

Hence, we need to determine whether a = -b or not.
With this understanding, let us now analyse the individual statements.

Step 3: Analyse Statement 1
As per the information given in statement 1, a = b – 4

•However,
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Problem Solving (PS) | Re: v, w, x, y, and z are five positive integers for which v≤w≤x≤y≤z. If t

May 31, 2019, 1:00 am

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Problem Solving (PS) | Re: By what factor should the smaller root of the equation 6x^2 -13x + 6 =

May 31, 2019, 1:00 am

≫ Next: Problem Solving (PS) | Re: 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%

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6x^2 -13x + 6 = 0
(3x-2)(2x-3)=0
Smaller root=2/3
Larger root=3/2
2/3*k=3/2
k=9/4

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Problem Solving (PS) | Re: 1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60%

May 31, 2019, 1:00 am

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x.........y
....60....
1.........3

$\frac{x-60}{60-y}$ =3/1
x+3y=240...(1)
x=240-3y=3(80-y)

We have 2 constraints
1. x=<100
2. x>y
Also, x will be a multiple of 3

x can be 99,96.....63
At x=60, y=60....Hence x can't take value equal to 60 or lower than 60.
Total number of integer values x can take=[$\frac{99-63}{3}$ ]+1=13

DisciplinedPrep wrote:

1 unit of x% alcohol is mixed with 3 units of y% alcohol to give 60% alcohol. If x > y, how many integer values can x take?

A. 10
B. 20
C. 35
D. 13
E. 30

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Data Sufficiency (DS) | Re: There are 6 floors in an apartment building.

May 31, 2019, 1:00 am

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shridhar786 wrote:

There are 6 floors in an apartment building. The mean number of residents in each apartment in the building is 2.3. How many apartments are in the building?

(1) On each floor, the number of apartments is between 2 and 4 inclusive.

(2) The total number of residents in the block is greater than 40

WTH IS WRONG WITH YOUR POSTS, MAN.
IT SAYS THERE ARE 2,3,4 APARTMENTS THERE
I TRIED SEVERAL POSSIBLE COMBINATIONS.
THE ULTIMATE EQUATION REMAINS
6X(2,3,4)/2.3
...

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Data Sufficiency (DS) | Re: In the sequence shown, a_n=a_(n-1)+k, where 2

May 31, 2019, 1:00 am

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Problem Solving (PS) | Re: The function f is defined as f(x,y) = xy for positive numbers x and y.

May 31, 2019, 1:00 am

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Shrey9 wrote:

nick1816 wrote:

f(x,1/x)=f(x,y)=xy=x*1/x=1
Now we know 2 things,y=1/x and f(x,y)=1

Hi thank you for the explanation. however, I am unable to see what is the value of X ?
is it 1/y ? from xy = 1 ?

Yes, xy=x*1/x or y=1/x or x=1/y

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Data Sufficiency (DS) | Re: Is xy > x^2 ? (1) y > x (2) y > 0

May 31, 2019, 1:00 am

≫ Next: Problem Solving (PS) | Edward invested five-ninths of his money at an annual rate of 2r% comp

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shridhar786 wrote:

Is xy > x^2 ?

(1) y > x

(2) y > 0

Can anyone tell me if I am doing the right way ?

given
xy > x^2
xy-x^2>0
x(y-x) >0
there exist two cases now for the questionnow
either x > 0
or y-x >0 or y>x

Now lets look at the statements

1) saysy>x but doesn't tell us anything about x>0 or x <0
therefore not sufficient

2) says y>0 but we don't know if x > 0 or not..
therefore, not sufficient

Combining 1 and 2
y>x rom 1
and y> 0 from 2
but what
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Problem Solving (PS) | Edward invested five-ninths of his money at an annual rate of 2r% comp

May 31, 2019, 1:00 am

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There are 2 approaches to solve thisquestion

1. Alligation Method
Edward invested five-ninths of his money at an annual rate of 2r% compounded semi-annually, his total interest would be slightly above 2r%.
We can use allegation method which would give us approximateanswer.

2r...................r
.....100/3.........
5....................4

$\frac{6r-100}{100-3r}$ =4/5
42r=900
r=21 which is closest to 20

2. General Approach Let principal amount = P

a. 5P/9 is invested at annual 2r% compounded semi-annually

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