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D day in two days Please Solve these Gprep DS


badar

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In data suff questions, work out an equation or target the answer before diving into the additional data.

 

1.

Let M = manager, D = director

 

Needed: D/(D + M)

 

(1) INSUFF, no information about D.

 

(2) INSUFF, no information about M.

 

(1) and (2):

 

Setup and equation for the averages:

 

15000D + (-5000M)/[M+D] = 0

 

Note: use 0 as the average since the data specifies above and below.

 

Solve to get: 1D to 3M, thus the percent of directors to managers is (1 director)/(4 total)

 

2.

 

This is a Venn Diagram question, and is best solved by drawing such a diagram and filling in the values.

 

An equation for this type of problem is:

 

Total = All_Group1 + All_Group2 - Both + Neither.

 

In this problem, the stem tells us that "each of the 128 people attended" so we can throw out the "Neither" portion of the formula above, and are left with:

 

128 = Morning_People + AfterNoon_People - Both.

 

Now, the trick is to recognize that both the Morning_People value and the AfterNoon_People value contain the Both value. (That is why you must subtract the Both value so you can eliminate that value when the two Group values overlap).

 

(1) INSUFF: Only tells you the Both parameter in the question.

 

(2). SUFF: This tells you that: AfterNoon_People_ONLY + Both = (7/8), thus (1/8) = Morning_People_ONLY. So the answer is (1/8)128

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In data suff questions, work out an equation or target the answer before diving into the additional data.

 

1.

Let M = manager, D = director

 

Needed: D/(D + M)

 

(1) INSUFF, no information about D.

 

(2) INSUFF, no information about M.

 

(1) and (2):

 

Setup and equation for the averages:

 

15000D + (-5000M)/[M+D] = 0

 

Note: use 0 as the average since the data specifies above and below.

 

 

How did you came up with the equation above?

I interpreted the statemnts as follows, where salary info is not given at all:

1) SMav = (SM + SD)/(M+D) - 5000

2) SDav = (SM+SD)/(M+D) + 15000

 

where

SMav = avg salary of M

SDav = avg salary of D

SM = total salary of M

SD = total salary of D

Average salary of any employee is (SM+SD)/(M+D)

 

There are too many unknowns, unless I am reading the stem wrong.

 

Could you please explain your equation again?

 

thanks

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hi malina ,

even i agre with your point ,

in short , with the info given ,

we an nt reach the

PERCENT OF DOCTORS , ,

STUCCO ,

pls advice , how did you arrived at the solution ,

thnx

mouse

 

What if I asked you to find the average weight of 7 poeple, 5 of whom weigh an average of 175 lbs and the other 2 whom weigh an average of 300 lbs? How would you set up and solve that equation?

 

Here's how:

 

[5(175) + 2(300)]/7 = 1475/7 ~ 210

 

Now apply that same concept here:

 

Let D = the number of directors. Likewise, let M = number of managers

Let A = the average of salary of both D and M

 

So,

 

Using (1) and (2) together (and remembering the above example) we get:

 

[(15000 + A)D + (A - 5000)M]/(D + M) = A

 

15000D + DA + MA - 5000M = DA + MA

 

15000D = 5000M

 

3D = M.

 

So, remeber our original desire was to solve D/(D + M)? Then just substitue M for 3D and get

 

D/(D + 3D) = D/4D = 1/4. Ans C.

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BOSS PLS UNDERSTAND THAT , IN YOUR EXAMPLE TO ME , YOU ARE TALKING - WEIGHT * , WEIGHT --- , N WEIGHT --

 

What if I asked you to find the average weight of 7 poeple, 5 of whom weigh an average of 175 lbs and the other 2 whom weigh an average of 300 lbs? How would you set up and solve that equation?

 

Here's how:

 

[5(175) + 2(300)]/7 = 1475/7 ~ 210

CAN YOU CALCULATE THE AGE OF - DOCTORS , IN YOUR EXAMPLE ,

THIS IS MY POINT ,

YOU ARE MIXING VERIABALES ,

no of mangers -L , NO OF DOCS = G

OK , AS PER ME THE EQN SHD BE -

M1+ M2 + --- Ml / L = ( M1 +-----Ml) +( D1 +------+ Dg ) / L+g -5000 ---- ( EQN -1 )

D1+D2 +---- +Dg / g = ( M1 +-----Mp) +( D1 +------+ Dg ) / L+G +15000

-------------- ( eqn-2 )

 

or isthere anything wrong im doing here , ---

can you pls solve this eqn

 

for g / L+g == ?

Now apply that same concept here:

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BOSS PLS UNDERSTAND THAT , IN YOUR EXAMPLE TO ME , YOU ARE TALKING - WEIGHT * , WEIGHT --- , N WEIGHT --

 

What if I asked you to find the average weight of 7 poeple, 5 of whom weigh an average of 175 lbs and the other 2 whom weigh an average of 300 lbs? How would you set up and solve that equation?

 

Here's how:

 

[5(175) + 2(300)]/7 = 1475/7 ~ 210

 

CAN YOU CALCULATE THE AGE OF - DOCTORS , IN YOUR EXAMPLE ,

THIS IS MY POINT ,

YOU ARE MIXING VERIABALES ,

no of mangers -L , NO OF DOCS = G

 

OK , AS PER ME THE EQN SHD BE -

M1+ M2 + --- Ml / L = ( M1 +-----Ml) +( D1 +------+ Dg ) / L+g -5000 ---- ( EQN -1 )

 

D1+D2 +---- +Dg / g = ( M1 +-----Mp) +( D1 +------+ Dg ) / L+G +15000

-------------- ( eqn-2 )

 

or isthere anything wrong im doing here , ---

can you pls solve this eqn

 

for g / L+g == ?

Now apply that same concept here:

 

Stucco is right and there is nothign wrong with your equation.

What stucco is saying is that there is another equation that we did not consider:

 

Equation A )

 

Average_salary_of_all = (Total_salary_of_doctors + Total_salary_of_managers) /(number_of_doctors + number_of_managers)

 

A = (avrg_salary_doctor * D + avg_salary_manager * M) /M + D

 

 

Stmt1) avrg_salary_doctor = Average_salary_of_all + 15000 = A + 15000

Stmt2) avrga_salary_manager = Average_salary_of_all - 5000 = A - 5000

 

Now replace avrg_salary_doctor and avg_salary_manager into Equation A

 

A = ((A + 15000 ) *D + (A - 5000) * M)/ M + D

 

A = (AD + 15000D + AM - 5000M )/ M + D

 

AM + AD = AD + 15000D + AM - 5000M

15000D = 5000M

M = 3D

 

Replace in D / D + M and voila.

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