Re: discrete math, how many zeroes in 125!

• To: mathgroup at smc.vnet.net
• Subject: [mg13440] Re: [mg13418] discrete math, how many zeroes in 125!
• From: Ken Levasseur <Kenneth_Levasseur at uml.edu>
• Date: Fri, 24 Jul 1998 01:45:30 -0400
• Organization: UMass Lowell Mathematical Sciences
• References: <199807230733.DAA05535@smc.vnet.net.>
• Sender: owner-wri-mathgroup at wolfram.com

```Tim:

If p is a prime, the number of factors of p in n! is equal to
Sum[Floor[n/(p^k)],{k,1,Infinity}].   The sum is finite since all but a
finite number of terms are zero.  Since there are plenty of 2's in
125!, you need only count the 5's.

Ken Levasseur
Math. Sci.
UMass Lowell

Timothy Anderson wrote:

> how can I solve this problem by counting the factors of 2 and 5 without
> doing each factor individually? thanks for any real quick help! Tim

```

• Prev by Date: Re: discrete math, how many zeroes in 125!
• Next by Date: Re: Gaussian Elimination wont work in my example
• Previous by thread: discrete math, how many zeroes in 125!
• Next by thread: Re: discrete math, how many zeroes in 125!