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The average (arithmetic mean) of 13 numbers is 70. If the av
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29 Aug 2018, 16:17
29 Aug 2018, 16:17
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The average (arithmetic mean) of 13 numbers is 70. If the average of 10 of these numbers is 90, what is the average of the other 3 numbers?
(A) \(-130\)
(B) \(\frac{10}{3}\)
(C) \(30\)
(D) \(90\)
(E) \(290\)
(A) \(-130\)
(B) \(\frac{10}{3}\)
(C) \(30\)
(D) \(90\)
(E) \(290\)
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Re: The average (arithmetic mean) of 13 numbers is 70. If the av
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09 Mar 2019, 05:50
09 Mar 2019, 05:50
1
sandy wrote:
The average (arithmetic mean) of 13 numbers is 70. If the average of 10 of these numbers is 90, what is the average of the other 3 numbers?
(A) \(-130\)
(B) \(\frac{10}{3}\)
(C) \(30\)
(D) \(90\)
(E) \(290\)
(A) \(-130\)
(B) \(\frac{10}{3}\)
(C) \(30\)
(D) \(90\)
(E) \(290\)
The average (arithmetic mean) of 13 numbers is 70.
We can write: (sum of all 13 numbers)/13 = 70
We get: sum of all 13 numbers = (13)(70) = 910
The average of 10 of these numbers is 90
We can write: (sum of the 10 numbers)/10 = 90
We get: sum of the 10 numbers = (10)(90) = 900
What is the average of the other 3 numbers?
The SUM of the 3 remaining numbers = (sum of all 13 numbers) - (sum of the 10 numbers)
= 910 - 900
= 10
So, the AVERAGE of the 3 numbers = (sum of the 3 numbers)/3
= 10/3
Answer: B
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Re: The average (arithmetic mean) of 13 numbers is 70. If the av
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21 Jun 2021, 12:12
21 Jun 2021, 12:12
2
Sum of 13 numbers = 13*70 = 910
Sum of 10 numbers = 9*10 = 900
910-900 = 10 ( sum of 3 numbers)
The avg of three numbers 10/3
hence, B is the answer
Sum of 10 numbers = 9*10 = 900
910-900 = 10 ( sum of 3 numbers)
The avg of three numbers 10/3
hence, B is the answer
