If n is the greatest positive integer for which 2^n is a factor of 10!, then n =?

A. 2

B. 4

C. 6

D. 8

E. 10

Solution:

On a closer look this Qs is asking how many 2s are there in multiplication of 10!

Now, as we know 10! can be written as -- 10.9.8.7.6.5.4.3.2.1

As this is a small multiplication ( To review , not to do), we can check how many 2s we have in this..,

So,

10-1 (no.of 2s),

8-3(no.of 2s),

6-1(no.of 2s),

4-2(no.of 2s),

2-1(no.of 2s)

Adding all, we'll have 1+3+1+2+1=8

Hence, ans. D.

Hope this helps

Dj.

_________________

Cheers..!!

Dj :)

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