GMAT Data Sufficiency Discussions

MBA GMAT
2123
neha.visionary Says
well i'm not sure what the answer should be. but i also don't understand why 2 is sufficient. i'm not able to get any set of 5 consecutive and set of 7 consecutive integers whose sum is same.


Well Neha, U have to consider the negative integers as well. With 0 being the median of those numbers. e.g {-2 ,-1, 0, 1, 2} I hope u got wat i mean ...But the problem is the answer is not B even. The answer as given is C and there is no explanation
2124
arnabray07 Says
Well Neha, U have to consider the negative integers as well. With 0 being the median of those numbers. e.g {-2 ,-1, 0, 1, 2} I hope u got wat i mean ...But the problem is the answer is not B even. The answer as given is C and there is no explanation


When u see a set of consecutive odd number of integers , average of that set is always equal to the median , i.e mean = median for odd number of consecutive integers.. You can algebrically prove this as well ..

stament 2 is not suff ..heres why
Take a case of sum which is multiple of both 5 and 7..
Say we take 35

Consider sum of S = 35 and so Sum of T =35..

S = 5,6,7,8,9
T = 2,3,4,5,6,7,8



Median of S = 7 and Median of T = 5..( Median = Avegare of such set as explained above)
So in this case answer to the question "Is the median of the numbers in set S equal to the median of the numbers in set T?
is 'NO'.

Other case of sum being equla could be S = 0


S = -2,-1,0,1,2
T = -3,-2,-1,0,1,2,3

But sum = 0 is also somthing which is divisible by 7 and 5 ( as 0 is divisible by all integers)
Here median = 0 for both S and Y and so answer to the question "Is the median of the numbers in set S equal to the median of the numbers in set T?" is 'YES'.. Thus stmnt 2 is not sufficient

But when you combine 2 stmnts you know for sure !
2125

A contractor combined x tons of gravel mixture that contained 10 percent gravel G, by weight, with y tons of a mixture that contained 2 percent gravel G, by weight, to produce z tons of a mixture that was 5 percent gravel G, by weight. What is the value of x?

(1) y = 10
(2) z = 16

2126

At a certain company, the average (arithmetic mean) number of years of experience is 9.8 years for the male employees and 9.1 years for the female employees. What is the ratio of the number of the company's male employees to the number of the company's female employees?

(1) There are 52 male employees at the company.

(2) The average number of years of experience for the company's male and female employees combined is 9.3 years.

2127

The sum of three integers is 60. What is the median?
1) one of the integers is 10
2) one of the integers is 20

2128
The sum of three integers is 60. What is the median?
1) one of the integers is 10
2) one of the integers is 20


The answer is C. both statement together
2129
The sum of three integers is 60. What is the median?
1) one of the integers is 10
2) one of the integers is 20


The OA is B.

If one of the integers is 20, there can be two cases:
1) If one of two other integers is less than 20, then the other integer should be greater than 20, in which case 20 will be the median.
2) If all the three integers are 20, then also 20 will be the median.

So B is the answer.
2130

is the answer C?


A contractor combined x tons of gravel mixture that contained 10 percent gravel G, by weight, with y tons of a mixture that contained 2 percent gravel G, by weight, to produce z tons of a mixture that was 5 percent gravel G, by weight. What is the value of x?

(1) y = 10
(2) z = 16
2131

statemnt 2 alone is sufficient

At a certain company, the average (arithmetic mean) number of years of experience is 9.8 years for the male employees and 9.1 years for the female employees. What is the ratio of the number of the companys male employees to the number of the companys female employees?

(1) There are 52 male employees at the company.

(2) The average number of years of experience for the companys male and female employees combined is 9.3 years.
2132
A contractor combined x tons of gravel mixture that contained 10 percent gravel G, by weight, with y tons of a mixture that contained 2 percent gravel G, by weight, to produce z tons of a mixture that was 5 percent gravel G, by weight. What is the value of x?

(1) y = 10
(2) z = 16

My answer is D.
Given statement gives us following 2 equations:
(i) x+y=z
(ii) 10x+2y=5z
We have 3 variables and 2 equations and we need one more equation to solve for x, y and z.

Statement 1: y=10; we can solve for x, y and z using this 3rd equation..hence, satisfies.
Statement 2: z=16; same here...we can solve for x, y and z using this 3rd equation..hence, satisfies.
2133
At a certain company, the average (arithmetic mean) number of years of experience is 9.8 years for the male employees and 9.1 years for the female employees. What is the ratio of the number of the company's male employees to the number of the company's female employees?

(1) There are 52 male employees at the company.

(2) The average number of years of experience for the company's male and female employees combined is 9.3 years.

My answer is B.

If x & y is is the total # of males and females respectively then we need x:y?

Statement1: no help
Statement2: can be rewritten as: (9.8x+9.1y)/(x+y) = 9.3. Using this equation we can solve for x:y.
2134
If digit h is the hundredths' digit in the decimal d = 0.2h6, what is the value of d, rounded to the nearest tenth?

(A) d
(B) h
2135
What is the value of X?
(A) When X is multiplied by 8, the result is between 50 and 60.
(B) When X is doubled, the result is between 10 and 15.

Stmt A: - 50

=> X = 7

stmt B : - 10

=> X = 6 , 7

So using only (A) ...but ans given ( E)
2136
What is the value of X?
(A) When X is multiplied by 8, the result is between 50 and 60.
(B) When X is doubled, the result is between 10 and 15.
Stmt A: - 50
=> X = 7
stmt B : - 10
=> X = 6 , 7
So using only (A) ...but ans given ( E)



The question does not mention tht X is an integer. It can well be a decimal number which when divided by 8 result lies between 50 and 60.
So there is no single answer for the question. Hence E is right.
2137

Could you please try this one:

If n is a positive integer, is the value of b-a at least twice the value of
3^n-2^n?

A. a=2^(n+1) and b=3^(n+1)
B. a=2

Please give the explanation for your answer.

2138

Taking A:
b-a=3^(n+1)-2^(n+1). solving this:

3^(n+1)-2^(n+1)=3.3^n-2.2^n
this shud be atleast twice of 2.3^n-2.2^n
as we can see this is true. so A alone is suffuicient.
solving

Taking B alone makes no sense as we do not know what the value of b is or n is.

so the answer is A.




Could you please try this one:

If n is a positive integer, is the value of b-a at least twice the value of
3^n-2^n?

A. a=2^(n+1) and b=3^(n+1)
B. a=2

Please give the explanation for your answer.
2139
If digit h is the hundredths' digit in the decimal d = 0.2h6, what is the value of d, rounded to the nearest tenth?
(A) d
(B) h


Did any one get a chance to check this question out ?
2140
bishoo123 Says
Did any one get a chance to check this question out ?

Each statement alone is sufficient
A says dB says h
2141

Qucik doubt here...
the question says h is the hundredth's digit of .2h6, but its go to be the tenth's digit. Is tht a typo?

Each statement alone is sufficient
A says dB says h
2142

I'll go with "A".

Statement1 gives d =0.2
Stement2: hcase1: h = 4, then d = 0.246 = 0.25 = 0.3 (to nearest tenth)
case2: h = 3, then d = 0.236 = 0.2 (to nearest tenth)
Two different answers for d. Hence only statement1 is sufficient.

Each statement alone is sufficient
A says dB says h