Math Is Fun Forum

I don't think I made it clear what I wanted, the way you showed it to me bob, that I know. But I'm talking about the rules  of exponenets. ex :

2^6/-2^5 =

I know it will give me a 2^1 in my answer, but I don't know if it will stay positive or not. I could do the calculations like you did bob, but how would I know directly without doing them ?

Nah, no brackets. But I'm not sure to have understood. Will there be a negative sign or not ??? And could you explain me why ? THanks

Ok, bye and thank you again. If it happens again, I'll remember to do a drawing like yours !

AH......... ok, Sh... I should have done a drawing to help me see it. Ok, now, I know how to finish do it.

Here's, in the ordrer of the diagramm, the probabilities :

0.096+0.024+0.224+0.056+0,144+0,036+0,336+0,084=1

GOOD!
Thank you bobbym, I've learned from it !

could you show me in details my error pls ?

Well, here's how I see it :

If 1 is our omega, the we SHOULD get this :
14% (Only one person) + 68 % (Only two persons, with the different variations of the two persons, because this is omega) + 9,6 % (The three of them hitting) + 8,4 % (none hitting) = 100 %

Ah, no I don't, I only had to find the probability of atleast 1 person hitting the target. But would the 0,14 that only one person hits the target be good, would it be the answer you would have chosen ?

Which one ? The 0,14 ?

Well, I got three of them

Two person hitting : 0,4 * 0,3= 0,12 or 0,4*0,8= 0,32 or 0,3*0,8=0,24

0,12+0,32+0,24= 0,68

I'm trying to get to 0 by substracting every probability. To be able to see in depth ^^

AHHHHHHH.. Thank you. THe problem was, I wasn't sure that atleast one person would also mean all the three like you showed me(It didn't make sense that it would mean ONLY one person, this is why I asked the question about it). A vocabulary problem ?

Anyway, thank you very much ! Im happy that I can count on this forum my problems

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. ?