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The average of 6 numbers is 19. When one of those numbers is removed, 04 Mar 2020, 05:51
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C
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5% (low)

Question Stats:

88% (01:01) correct 12% (01:55) wrong based on 84 sessions

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The average of 6 numbers is 19. When one of those numbers is removed, the average of the remaining 5 numbers is 21. What number was taken away?

(A) 2
(B) 8
(C) 9
(D) 11
(E) 20
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C
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The average of 6 numbers is 19. When one of those numbers is removed, 04 Mar 2020, 07:21
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The average of 6 numbers is 19. When one of those numbers is removed, the average of the remaining 5 numbers is 21. What number was taken away?

(A) 2
(B) 8
(C) 9
(D) 11
(E) 20

required number = 19*6 - 21*5 = 9
Ans :C
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The average of 6 numbers is 19. When one of those numbers is removed, 04 Mar 2020, 10:04
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SajjadAhmad
The average of 6 numbers is 19. When one of those numbers is removed, the average of the remaining 5 numbers is 21. What number was taken away?

(A) 2
(B) 8
(C) 9
(D) 11
(E) 20
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\(19*6 - 5*21 = 114 - 105 = 9\), Hence Answer must be (C)
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The average of 6 numbers is 19. When one of those numbers is removed, 05 Mar 2020, 04:40
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SajjadAhmad
The average of 6 numbers is 19. When one of those numbers is removed, the average of the remaining 5 numbers is 21. What number was taken away?

(A) 2
(B) 8
(C) 9
(D) 11
(E) 20
Show more

Method 1:
Sum of those 6 numbers = 19*6 = 114

Sum of remaining 5 numbers = 21*5 = 105

Removed number = 114-105 = 9

Method 2:

Change of average = 21-19 = 2

i.e. the difference in sum that the removed number brought = 2*5 = 10

i.e number removed must have been 10 units less than the previous average which is 19

i.e. Number removed = 19 - 10 = 9

Answer: Option C
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The average of 6 numbers is 19. When one of those numbers is removed, 06 Mar 2020, 00:35
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The average of 6 numbers is 19, so the sum of all the numbers will be 114.
When 1 number is removed, then we can assume that number removed is 'x'.
So, 114-x/5=21, then 114-x=105,
Hence, the value of x is 9
i.e, Option C

Thank you!
Cheers!

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Raunak Damle
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The average of 6 numbers is 19. When one of those numbers is removed, 06 Mar 2020, 08:35
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SajjadAhmad
The average of 6 numbers is 19. When one of those numbers is removed, the average of the remaining 5 numbers is 21. What number was taken away?

(A) 2
(B) 8
(C) 9
(D) 11
(E) 20
Show more

Solution:

We can create the equation:

(6 x 19 - n)/5 = 21

114 - n = 105

n = 9

Alternate Solution:

The sum of the original 6 numbers is 6 x 19 = 114. The sum of the numbers after one has been removed is 5 x 21 = 105. Thus, the number that was removed is 114 - 105 = 9.

Answer: C
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