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The average (arithmetic mean) of eleven numbers is 15. When
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12 Nov 2020, 10:28
12 Nov 2020, 10:28
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96% (00:40) correct
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The average (arithmetic mean) of eleven numbers is 15. When a twelfth number is added, the average of the twelve numbers is 14.
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.
Source: 320 GRE Math Questions
Quantity A |
Quantity B |
The twelfth number |
4 |
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.
Source: 320 GRE Math Questions
Re: The average (arithmetic mean) of eleven numbers is 15. When
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12 Nov 2020, 14:47
12 Nov 2020, 14:47
1
We can determine the sum of the numbers, x, bu using this formula x/11 = 15. Solve for x and we get 165. To compare the quantities, we must calculate a new mean using 4. (165+4)/12 = 14.083. Since this average is greater than the given one, we know the twelfth number must be less than 4. Quantity B is greater.
Re: The average (arithmetic mean) of eleven numbers is 15. When
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13 Nov 2020, 22:28
13 Nov 2020, 22:28
1
Given: sum of 11 numbers/11 = 15.
==> Sum of 11 numbers = 15 * 11.
Sum of 11 numbers = 165.
(Sum of 11 numbers + 12th number)/12 = 14.
165 + 12th number = 168.
12th number = 168 - 165 ==> 3.
3 < 4. So correct answer is Qty B.
Posted from my mobile device
==> Sum of 11 numbers = 15 * 11.
Sum of 11 numbers = 165.
(Sum of 11 numbers + 12th number)/12 = 14.
165 + 12th number = 168.
12th number = 168 - 165 ==> 3.
3 < 4. So correct answer is Qty B.
Posted from my mobile device
