Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

You are not logged in.

## #1 Re: Ganesh's Puzzles » Oral puzzles » 2006-03-15 07:22:00

mathsy, 2 easy ways of getting approximate answers to 20 without a calculator:-

a) every power of 10 requires just over 3 powers of 2. Therefore 50 powers of 2 suggests between 15 and 16 powers of 10.
b) If you know that log 2 = 0.3010 (which you should!), then log 2^50 = 15.05. Again, about 15 powers of 10

By both methods, this gives me 16 digits in the answer.

## #2 Re: Jokes » "sharing" » 2006-03-12 13:43:09

I shouldn't laugh........ but I did! Lots!

## #3 Re: Help Me ! » i need help with this math problem » 2006-03-12 09:52:07

I took the question literally:

14 people (humans) = 28 eyes
2 martians = 6 eyes

## #4 Re: Guestbook » math » 2006-03-12 09:47:06

I am married to a Filipino and we have a house there. Yes, that was the 2nd major mudslide in the past year, but fortunately not near where our family live. Alas, it shows what happens when corrupt commercialism is allowed to chop down the forests.

## #5 Re: Puzzles and Games » Can you solve it? » 2006-03-12 03:10:03

Mathsy, you CAN divide by 0 - damathematician just did so......... it just gives you wrong answers, so we don't do it!!!

## #6 Re: Puzzles and Games » A Powerful Puzzle » 2006-03-11 22:06:05

mathsyperson wrote:

Well, not entirely, but it is right if you've roundeded it. But the real question is... what is 1.414 more commonly expressed as?

Mathsy, yes, I did round it and I do I know what it is expressed as - just wanted to leave something in the puzzle for someone else!

## #7 Re: Puzzles and Games » A Powerful Puzzle » 2006-03-11 13:44:08

If I am right about the first one, I reckon that solving for 10 would only give a very slightly higher answer, but I don't have the time right now!

## #9 Re: Guestbook » math » 2006-03-11 13:17:04

Tigeree wrote:

Memento ??? where da u live ?

Tigeree, are the two questions connected?

Memento is an absolutely brilliant suspense movie about a guy with short-term memory loss. It's a really weird film that actually runs backwards and is pretty scary and hugely thought-provoking when you get into what is actually happening.

Me, I live in Devon, UK & sometimes Philippines

## #10 Re: Puzzles and Games » A Powerful Puzzle » 2006-03-11 07:36:22

This one is hurting my brain!

## #11 Re: This is Cool » Cassini Finds an Active, Watery World at Saturn's Enceladus » 2006-03-11 04:21:45

Isn't that how scientific knowledge advances? By jumping to conclusions (more formally known as "formulating hypotheses"). The key is to realise when one's testing of such conclusions is clouded by nothing more than determination that they must be correct!

## #12 Re: Guestbook » math » 2006-03-11 04:11:59

Ever watched "Memento"?

## #13 Re: Guestbook » math » 2006-03-11 04:10:54

Maybe I did read it here, but for me it was a distant and fuzzy memory. It was as far back as I can remember, so forgive me if I forget some of the details

## #14 Re: Guestbook » math » 2006-03-11 03:52:56

I once heard someone say that goldfish can only remember the last 5 seconds.........

## #15 Re: Ganesh's Puzzles » Brain Teasers » 2006-03-11 03:48:59

Once 3(a) and 3(b) are answered, 3(c), (d), (e) are just extensions of the same principles

3 (b)

3 (a)

## #19 Re: Ganesh's Puzzles » Brain Teasers » 2006-03-11 02:51:19

Sorry, posted wrong answer to (2)! Try again!!

SDT #5

## #22 Re: This is Cool » Red Rain Over India - Alien Life? » 2006-03-09 11:44:50

Ricky, I would love to debate the role of amino acids in the formation of life, but the truth is that I have no idea! Just playing with you. (though I do have a myriad controversial opinions on evolution/creation, god/atheism etc, but best not here)

#2

## #24 Re: Ganesh's Puzzles » Speed, Distance, Time » 2006-03-09 11:11:04

SDT #4

I like this one! Some good red herrings. Started off thinking about what time dad left home; what is the distance from school to home? did dad always manage to arrive exactly on time? why did he call his son "X"? Actually, none of it is relevant (but I do feel sorry for the poor boy branded with such a name)

## #25 Re: Ganesh's Puzzles » Speed, Distance, Time » 2006-03-09 10:40:59

SDT #3

Assumption: The definition of "passing" means from the moment the front of the train starts to pass until the moment that the end of the train finishes passing.

The trains initially are heading toward each other. Therefore, their combined speed is 72 + 45 = 117kph

It takes 30 seconds for them to pass, so the combined length of the trains is 117/120 km

When travelling in the same direction, the differential speed is only 27kph.

In order to travel 117/120km at 27kph, it will take:

(117/120) * (60/27) minutes = 2.1666 minutes = 2 minutes 10 secs