If n is the product of the integers from 1 to 70, inclusive, what is the greatest integer m for which 7^m is a factor of n/7^2?
(A) 2
(B) 7
(C) 9
(D) 11
(E) 14
OA: [spoiler]C: 9[/spoiler]
Source: Knewton
factors
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- harsh.champ
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n = 70!rahul.s wrote:If n is the product of the integers from 1 to 70, inclusive, what is the greatest integer m for which 7^m is a factor of n/7^2?
(A) 2
(B) 7
(C) 9
(D) 11
(E) 14
OA: [spoiler]C: 9[/spoiler]
Source: Knewton
n/7^2 = 70!/49
In 70 ! 7 comes in 7,14,21,28,35,42,49,56,63,70
Now we have excluded 49
Thus 7 occurs 9 times
Hence ,C should be the answer.
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If 7^m is a factor of n/7^2,rahul.s wrote:If n is the product of the integers from 1 to 70, inclusive, what is the greatest integer m for which 7^m is a factor of n/7^2?
(A) 2
(B) 7
(C) 9
(D) 11
(E) 14
OA: [spoiler]C: 9[/spoiler]
Source: Knewton
then 7^ (m + 2) is a factor of n
Need to know the greatest degree of 7 in 1 × 2 × 3 × ...69 × 70, is it 7^10? NOPE, do not forget 49, YEAH, it is 7^11. Hence, the greatest integer m for which 7^ (m + 2) is a factor of n, is 11 - 2 = [spoiler]9[/spoiler].
[spoiler]C[/spoiler]
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- harsh.champ
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A very easy question since it is written n/7^2
We can easily identify 49
Also,in the answer choices 8 should also be given to confuse the test-takers.
Then there could have been chances of ppl answering 10-2 =8 is the answer.
I am sure if sanju09 had framed the ques. it would have been something I had written above.
What-say??
We can easily identify 49
Also,in the answer choices 8 should also be given to confuse the test-takers.
Then there could have been chances of ppl answering 10-2 =8 is the answer.
I am sure if sanju09 had framed the ques. it would have been something I had written above.
What-say??
It takes time and effort to explain, so if my comment helped you please press Thanks button
Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.
"Keep Walking" - Johnny Walker
Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.
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- thephoenix
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when 70! div by 7-------->10 is the quotientrahul.s wrote:If n is the product of the integers from 1 to 70, inclusive, what is the greatest integer m for which 7^m is a factor of n/7^2?
(A) 2
(B) 7
(C) 9
(D) 11
(E) 14
OA: [spoiler]C: 9[/spoiler]
Source: Knewton
10/7------>1 is the q
total 11 times 7
7^11/7^2=7^9-------> 9 is the ans