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Dataset A consists of 5 numbers, which have an average (arit
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30 Aug 2018, 07:31
30 Aug 2018, 07:31
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Question Stats:
60% (01:48) correct
39% (01:53) wrong based on 243 sessions
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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
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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
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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.
