GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Dataset A consists of 5 numbers, which have an average (arit
[#permalink]
30 Aug 2018, 07:31
30 Aug 2018, 07:31
5
1
Expert Reply
3
Bookmarks
00:00
Question Stats:
60% (01:49) correct
39% (01:53) wrong based on 250 sessions
Hide Show timer Statistics
Dataset A consists of 5 numbers, which have an average (arithmetic mean) value of 43. Dataset B consists of 5 numbers.
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
The value of x if the average of x and the 5 numbers in dataset A is 46. |
The average of dataset B if the average of the 10 numbers in datasets A and B combined is 52. |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Re: Dataset A consists of 5 numbers, which have an average (arit
[#permalink]
10 Sep 2018, 11:08
10 Sep 2018, 11:08
2
(43*5+x)/6=46 => x=61
(52*10-43*5)/5=61
ans C
(52*10-43*5)/5=61
ans C
Re: Dataset A consists of 5 numbers, which have an average (arit
[#permalink]
26 Sep 2018, 22:27
26 Sep 2018, 22:27
4
While @Saifee's answer is correct, it may take some time to do some multiplications. In the GRE you've got to be quick and look for short cuts.
First let's solve A :
x is some value added to the Dataset A which makes it's average increase from 43 to 46.
There are 5 elements in Dataset A , so to increase avg from 43 to 46, it's as good as adding 3 to each of the 5 elements. After this, the average is 46 in Dataset A and we also have to add x (sixth element) while making sure that avg remains 46. So what value of x will keep the avg 46 ? x = 46 will do that.
Now, the new element added is 3*5 + 46 = 61.
Solve B :
Since we are finding avg of 2 lists with same number of elements, we can simply average the averages. That is,
(43 + X)/2 = 52
X = 61
Hence answer is C.
This seems long but once you get the hang of it, you can avoid long calculations and can do all this mentally.
First let's solve A :
x is some value added to the Dataset A which makes it's average increase from 43 to 46.
There are 5 elements in Dataset A , so to increase avg from 43 to 46, it's as good as adding 3 to each of the 5 elements. After this, the average is 46 in Dataset A and we also have to add x (sixth element) while making sure that avg remains 46. So what value of x will keep the avg 46 ? x = 46 will do that.
Now, the new element added is 3*5 + 46 = 61.
Solve B :
Since we are finding avg of 2 lists with same number of elements, we can simply average the averages. That is,
(43 + X)/2 = 52
X = 61
Hence answer is C.
This seems long but once you get the hang of it, you can avoid long calculations and can do all this mentally.
