Microsoft Office Tutorials and References

In Depth Information

**Using the rounding functions**

The COMBIN function

The COMBIN function determines the number of possible combinations, or groups, that

can be taken from a pool of items. It takes the arguments (
number, number_chosen
), where

number
is the total number of items in the pool and
number_chosen
is the number of

items you want to group in each combination. For example, to determine how many

different 11-player football teams you can create from a pool of 17 players, type the formula

=COMBIN(17, 11)
. The result indicates that you could create 12,376 teams.

Try your luck

The COMBIN function can help you figure out just how slim a chance you have of

drawing the elusive ace-high straight lush in a game of five-card stud. You express

the number of 5-card combinations by using the formula =COMBIN(52, 5),

resulting in 2,598,960. That’s not too bad when you consider the odds of winning the

lottery. For a lotto game in which you select 6 numbers out of a total of 49, the formula

=COMBIN(49, 6) reveals that there are 13,983,816 possibilities. You’d better keep your

day job either way.

The RAND and RANDBETWEEN functions

The RAND function generates a random number between 0 and 1. It’s one of the few Excel

functions that doesn’t take an argument, but you must still type a pair of parentheses after

the function name. The result of a RAND function changes each time you recalculate your

worksheet. This is called a
volatile
function. If you use automatic recalculation, the value of

the RAND function changes each time you make a worksheet entry.

The RANDBETWEEN function provides more control than RAND. With RANDBETWEEN,

you can specify a range of numbers within which to generate random integer values.

The arguments (
bottom, top
) represent the smallest and largest integers that the

function should use. The values for these arguments are inclusive. For example, the formula

=RAND BETWEEN(123, 456) can return any integer from 123 up to and including 456.

Using the rounding functions

Excel includes several functions devoted to the seemingly narrow task of rounding numbers

by a specified amount.