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The arithmetic mean of 3, 6, 9, a, b is 6.2
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02 Feb 2022, 11:49
02 Feb 2022, 11:49
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The arithmetic mean of 3, 6, 9, a, b is 6.2
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
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Quantity A |
Quantity B |
6 - a |
b - 6 |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Posted from my mobile device
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The arithmetic mean of 3, 6, 9, a, b is 6.2
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02 Feb 2022, 12:09
02 Feb 2022, 12:09
1
Sumukh19 wrote:
The arithmetic mean of 3, 6, 9, a, b is 6.2
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Posted from my mobile device
Quantity A |
Quantity B |
6 - a |
b - 6 |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Posted from my mobile device
Nice question!
Given: The arithmetic mean of 3, 6, 9, a, b is 6.2
We can write: \(\frac{3+6+9+a+b}{5} = 6.2\)
Multiply both sides of the equation by 5 to get: \(3+6+9+a+b = 31\)
Simplify: \(18+a+b = 31\)
Subtract \(18\) from both sides: Simplify: \(a+b = 13\)
We have:
QUANTITY A: 6 - a
QUANTITY B: b - 6
Let's apply some matching operations (my favorite technique! See video below for more information)
Add 6 to both quantities to get:
QUANTITY A: 12 - a
QUANTITY B: b
Add a to both quantities to get:
QUANTITY A: 12
QUANTITY B: a + b
Since we already learned that \(a+b = 13\), we can substitute to get:
QUANTITY A: 12
QUANTITY B: 13
Answer: B
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The arithmetic mean of 3, 6, 9, a, b is 6.2 [#permalink]
02 Feb 2022, 12:09
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