HP 30b Professional manual 15I3h, Binomial Functions, Two-Number Functions, Combination=, r!n - r

Binomial Functions

The binomial function calculates the probability of having up to k successes out of n throws,

when the probability of success is p. Enter n and p each followed by =and type k and navigate to the binomial function in the math menu.

Two-Number Functions

Apart from +-*/, the three additional two-number functions accessible on the keyboard are:

•yx

•nCr

•nPr

yx is the power function, nCr stands for the number of combinations of n items taken r at a time, and nPr stands for the number of permutations of n items taken r at a time.

n!

Combination= ----------------------

r!(n – r)!

Permutation=	n!
	(---n----–-----r---)--!

Perform calculations with these functions in the same way you would perform calculations with +-/and *, but press :to access the secondary function key. For example, to calculate 153 :

1. Press 15.

2. Press :h.

3. Press 3=. The result is shown in Figure 9.

Figure 9

In RPN mode, key in the numbers first, followed by I, then press the function key. For example, for the power function example above, in RPN press:

15I3:h.

Mathematical Calculations 23