Mathematics is easy

reinloch

This doesn't look like maths...or does it?

If it is a coal, then it is black.
which is correct?
A) If it is black, then it is a coal.
B) If it is not black, then it is not a coal.
C) If it is not a coal, then it is not black.

yassin_yahya

.  

If it is a coal, then it is black.

mathematically this represent: if    it = coal, then it = black. so coal=black (but literally coal ≠ black)

A) If it = black , then it=coal. so black=coal
B) if it ≠ black , then it ≠ coal. so either coal=black or coal≠black
C) if it ≠ coal, then it ≠ black. so either coal=black or coal≠black

mathematically (A) is equavalent......


confusing huh? doesnt look like math but i beleive we can solve using mathematic.

yassin_yahya

for fun...may be these are easy for some of you...

1. A harmonica cost a dollar more than a pencil. together they cost $1.10. how much did it costs?

2. Farmer Brown came to town with some watermelons. he sold half of them plus half a melon and found that he had one whole melon left. How many melons did he take to town?

reinloch

If it is black, then it is a coal.
Hair, night sky, etc are also black. If it is black, it is not necessarily coal.

If it is not a coal, then it is not black.
Hair, night sky, etc are also black. If it is not coal, it is not necessarily not black.

If it is a coal, then it is black. This proposition is logically equivalent to its contrapositive: If it is not black, then it is not a coal.

Don't we just love logic?

reinloch

an oldie:

Ahmad, Bala and Chong Ming went to KL to watch the new year celebrations, and arrived the night earlier. They then proceeded to bunk up at the nearest lodgings they could find. It was RM30 for the night, so each of them paid RM10. However, as they were unpacking, the manager came to return RM5, and told  them  there was a 20% discount for the new year bash. The problem was, they couldn't divide the RM5 among themselves, so they gave  the honest manager a RM2 tip. Now, each of them paid RM10 earlier, and now got back RM1. So, each of them actually paid RM9, which amounts to RM27 total. Plus, they gave the manager RM2, so that's RM29 altogether.... waidaminnit ... ... twhere's the remaining RM1????

rudz

Originally posted by reinloch at 3-2-2007 05:45 PM
This doesn't look like maths...or does it?

If it is a coal, then it is black.
which is correct?
A) If it is black, then it is a coal.
B) If it is not black, then it is not a coal.
C ...

Dalam maths ataupun lebih tepat mantik cuma pernyataan yang berikut betul bagi pernyataan di atas;

If it is not black, then it is not a coal

rudz

Originally posted by reinloch at 4-2-2007 12:32 PM
If it is black, then it is a coal.
Hair, night sky, etc are also black. If it is black, it is not necessarily coal.

If it is not a coal, then it is not black.
Hair, night sky, etc are also b ...

argument dlm maths bagi pernyataan di atas adalah,

If it is black, then it is a coal
so,
when it is not a coal, therefor it is not black... that is ...

tiada pertambahan fakta ataupun penambahan hujah...
penambahan hujan yg diberi....merupakan hujah yg tidak valid melainkan hubungan hair, night sky dan etc kepada coal dan black diberi secara jelas dan sah..

reinloch

I was merely explaining why the inverse and converse are not equivalent to the original proposition using some simple examples.

yassin_yahya

   the manager already took RM 1 earlier....

reinloch

They gave RM25 after discount + RM2 tips. Total is RM27.

yassin_yahya

aku_EnSeM

The best book of nature is a book that is written in mathematical language...'

Remind me who said this!!!! He is not a mathematician in this century.

prototaip

:setuju:

Aku rasa peliklah....Sunyi betul ruangan Science Technology and Maths ni ye.
Ruangan lain happening je.
Adakah tiada budaya ilmu sains dan matematik di kalangan kita?musykil,musykil....

yassin_yahya

who?      :hmm:

yassin_yahya

tiada lah tu kalau senyap adan sunyi.........