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Which of the following is NOT a factor of 20!?
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05 Nov 2017, 01:44
05 Nov 2017, 01:44
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Question Stats:
62% (00:57) correct
37% (00:14) wrong based on 35 sessions
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Which of the following is NOT a factor of 20! ?
A. 17
B. 21
C. 25
D. 29
E. 42
F. 51
G. 85
H. 121
Kudos for correct solution.
A. 17
B. 21
C. 25
D. 29
E. 42
F. 51
G. 85
H. 121
Kudos for correct solution.
Show: :: OA
D. and H.
Re: Which of the following is NOT a factor of 20!?
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05 Nov 2017, 03:05
05 Nov 2017, 03:05
In order not to be a factor of 20!, a number must no be between 1 and 20 and it cannot be computed as the product of numbers contained in 20!. Ths means that 29, which is prime and greater than 20 and 121 which is 11*11 and in 20! we have just one 11 are not factors of 20! Answers D and H.
The others are either between 1 and 20 such as 17 or they can be computed as products of factors of 20! such as 42 = 6*7.
The others are either between 1 and 20 such as 17 or they can be computed as products of factors of 20! such as 42 = 6*7.
Re: Which of the following is NOT a factor of 20!?
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24 Nov 2018, 15:12
24 Nov 2018, 15:12
Hi, i think that 25 could not be a factor of 20! because it is 5*5 but we have just one 5, am i right?
