ashikaverma13 wrote:

ashikaverma13 wrote:

What is the largest value of non negative integer N for which 10N is a factor of 50!?

A. 5

B. 6

C. 12

D. 15

E. 20

Thanks for your response!

Could you elaborate a bit more on the reasoning?

why do we have to find the no of 5s and how exactly did it come to 12?

Hi,

The reasoning for these type of Qs is...

What does ! Or factorial mean ..

It means product of all positive integers till that number..

So 50! Means 1*2*3*4*5....*49*50

Now when we multiply 2 and 5 we get a 10..

So 2s will be more than 5s and that is why number of 10s will be equal to number of 5s...

Now how do we find number of 5s in 50!..

When you divide by 5 you get all multiples of 5 till 50..

50/5=10..

These 10 numbers are 5,10,15,20,25,30,35,.40,45,50..

When we divide by 25 we get numbers which had 5^2 in it..

50/25 =2..

And these are 25 Aand 50..

So you have 12 5s or 10s..

Can you please explain from here onwards "So 2s will be more than 5s and that is why number of 10s will be equal to number of 5s..."