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

You are not logged in.

|
Options

bobbym
2013-03-30 12:19:05

For probability and combinatorics when stuck I do it the hard way. No calculations, draw trees or count them all by hand.

Al-Allo
2013-03-30 12:08:48

anyway, ill go through what you posted tomorrow, i dont have the energy tonight to think about it. thanks for your efforts to help.*curiously, when you get stuck on problems, how do you operate to solve them? any principles,etc. ?

bobbym
2013-03-30 11:57:45

Here is the full tree do you know what to do from here? Pay no attention to the numbers after the words circle triangle or hexagon.

Al-Allo
2013-03-30 11:37:46

bobbym
2013-03-30 11:34:57

The question is the same as the one you posted in post #1. The answer and logic are the same, 4 / 9. I can draw a tree if it will help.

Al-Allo
2013-03-30 11:22:11

Here :

An aleatory experience consists of turning an arrow on a roulette two times. (3 triangles, 1 circle, and two hexagon)

Question : What is the probability of obtaining exactly one haxagon.

bobbym
2013-03-30 11:13:09

If you are not sure of the problem then please just copy it over here.

Al-Allo
2013-03-30 11:09:30

i think im gonna re read the problem... im not sure of even understanding what they want ..ty for your help

bobbym
2013-03-30 10:59:58

ho means I drew a hexagon and then something else. The probability of drawing a h is 2 / 6 because there are 2 of them out of the total 6. Then I draw an o, the probability is ( 4 / 6 ) because there are 4 of them out of 6. Same logic for oh.

Al-Allo
2013-03-30 10:54:49

it gives 16/36

but i still don't understand the logic behind it   how did you get those numbers ?ty

bobbym
2013-03-30 10:50:59

Hi;

oh = ( 4 / 6 ) ( 2 / 6 )
ho = ( 2 / 6 ) ( 4 / 6 )

oo = who cares
hh = who cares

Can you finish that?

Al-Allo
2013-03-30 10:47:55

ok...

explain this
oh
ho
oo
hh

bobbym
2013-03-30 10:44:28

You always have to get an answer. One way, or the other.

Let me show you how to draw the tree without drawing it:

This is your set of possibilities,

now the triangles and the circle we are not interested in so we give them the generic label of "other." Your set becomes,

the tree looks like this,

oh
ho
oo
hh

do you follow?

Al-Allo
2013-03-30 10:40:05

yes. and what do you mean by simplest ideas ?

bobbym
2013-03-30 10:37:08

Hi;

For school problems you should be using the simplest ideas, especially when you are stuck. Did you draw a tree?