Cowdog Posts: 1, Reputation: 1 New Member #1 Nov 12, 2017, 11:41 AM
Difficult math problem:
How many times do write digit 1 if you write all possible natural numbers up to seven digits using digits 0 and 1 only?
 smoothy Posts: 25,495, Reputation: 2853 Uber Member #2 Nov 12, 2017, 11:45 AM
What do you think and why?

 Question Tools Search this Question Search this Question: Advanced Search

## Check out some similar questions!

Difficult math word problem. [ 15 Answers ]

I need this problem solved step by step with formula if anybody could solve it :::::find the length of three metals (hold the bridge)if the length is 80 inch and the width is 200 inch?

How to solve the difficult love problem ? [ 6 Answers ]

Hi, I want to know some ways. I am now interesting a girl and I want to propose to her. She is 5 years older than me. As she is older than me, everybody can guess that she have many experiences than me. Ya, it is true. She is smart and friendly. In her mind, I am just kid and like her...

Very difficult math equation [ 9 Answers ]

Prove it!

Difficult Distinguishable Permutation Problem [ 6 Answers ]

Consider three-letter "words" to be formed by using the vowels a, e, I, o, and u. How many different words without repetitions can be formed whose letters at the ends are you and I? I need a detailed explanation as well. Thanks!

Very difficult hacking/virus problem [ 5 Answers ]

Question - Very difficult hacking/virus problem. My computer is suffering a lot of crashes etc, especially when on the internet. This is what happened... I received an e-mail said to be from paypal saying that I had been registered etc. As that wasn't true I opened it to read it. That's...