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Can anybody give me a good advice how can I calculate the following probability example on my HP-20S?

p= Cn,r(5,2) × Cn,r(85,3) ÷ Cn,r(90,5)

The right result is for FIX 4 is 0.0225

Thanks!
Csaba
(04-16-2015 04:13 PM)Csaba Tizedes Wrote: [ -> ]Can anybody give me a good advice how can I calculate the following probability example on my HP-20S?

p= Cn,r(5,2) × Cn,r(85,3) ÷ Cn,r(90,5)

The right result is for FIX 4 is 0.0225

Thanks!
Csaba

If you use registers it can easily be done with
5 INPUT 2 Cn,r STO 0
85 INPUT 3 Cn,r STO 1
90 INPUT 5 Cn,r STO 2
RCL 0 x RCL 1 / RCL 2 =

Bernhard
(04-16-2015 05:03 PM)PANAMATIK Wrote: [ -> ]If you use registers...

Thanks Bernhard - I figured out it also, but if I ask my question as "Can anybody give me a good advice how can I swim across the Atlantic Sea?" And you answer it as "If you use a boat it can easily be done", you can see that the "sailing" and "swimming" is not the same things...

I tried it with some ways on my HP (for example with "forced" parentheses) and it is not works. I really like this little algebraic calc and I really like to use its functions, programming, statistics, and so on... but it's a sad thing to find a bug in the data entry routine.

My calc is not here now, but I think I'll try all the functions which are use the INPUT key.

Csaba
Thanks for your explanation - I first thought you were looking for a way to simplify the problem e.g. by cancelation of terms.

d:-/
(04-16-2015 07:38 PM)Csaba Tizedes Wrote: [ -> ]
(04-16-2015 05:03 PM)PANAMATIK Wrote: [ -> ]If you use registers...

Thanks Bernhard - I figured out it also, but if I ask my question as "Can anybody give me a good advice how can I swim across the Atlantic Sea?" And you answer it as "If you use a boat it can easily be done", you can see that the "sailing" and "swimming" is not the same things...

I tried it with some ways on my HP (for example with "forced" parentheses) and it is not works. I really like this little algebraic calc and I really like to use its functions, programming, statistics, and so on... but it's a sad thing to find a bug in the data entry routine.

Csaba

Hi Csaba,

Of course, I tried the parentheses too, and it didn't work. The parentheses were just ignored. It is well known that the HP-20S behaviour is not consistent. Ignoring parentheses in an algebraic calculator is a bug. Perhaps there is a little relict of RPN left inside.

You have to take the sailing boat.

Bernhard
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