## Welcome to BrainDen.com - Brain Teasers Forum

Welcome to BrainDen.com - Brain Teasers Forum. Like most online communities you must register to post in our community, but don't worry this is a simple free process. To be a part of BrainDen Forums you may create a new account or sign in if you already have an account. As a member you could start new topics, reply to others, subscribe to topics/forums to get automatic updates, get your own profile and make new friends. Of course, you can also enjoy our collection of amazing optical illusions and cool math games. If you like our site, you may support us by simply clicking Google "+1" or Facebook "Like" buttons at the top. If you have a website, we would appreciate a little link to BrainDen. Thanks and enjoy the Den :-) |

# No. of digits in this number...

### #1

Posted 22 July 2007 - 09:39 PM

what is the number of digits in the number

345893456 ^ 345893456 (read as the number raised to itself)

oh yeah, feel free to use ur calculators, super-computers, grids, etc..

### #2

Posted 02 August 2007 - 01:11 AM

The 50-50-90 rule: Anytime you have a 50-50 chance of getting something right, there's a 90% probability you'll get it wrong

### #3

Posted 02 August 2007 - 01:39 AM

Do you know the answer?

The 50-50-90 rule: Anytime you have a 50-50 chance of getting something right, there's a 90% probability you'll get it wrong

& yes, i was given this problem recently and was given ten min's to figure it out, thankfully it struck in the 1st min...

Number of digits # 10 ^ 2953564278

Now, here's the tough / easy part given the answer: Explain the reasoning

### #4

Posted 02 August 2007 - 04:36 AM

345893456 * log(345893456)

### #5

Posted 02 August 2007 - 05:37 PM

It took me a little while, but once I got it I see how someone else could get it much quicker than I did. I would have been pushing the 10 minute time limit.

345893456 * log(345893456)

Bingo!!

### #6

Posted 03 August 2007 - 01:16 AM

### #7

Posted 03 August 2007 - 04:22 AM

i dont understand... using Log on the second number changes the equation, doesnt it?

Of course it does, hence the 10 ^ ____ in the answer!

y = x^x (read raised to)

log y = x * log x (log to the base 10)

Now go back to logarithmic basics and think!

#### 0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users