If we start with 10 choices, have 5 decisions to make/positions to fill, and repetition isn’t allowed, how many combinations can be made?

252?

yes

and with repetition, it is 2002?

how did you get 2002 ?

You are making decisions and repetition is allowed?
Are you making the same decisions more than once??

it asks this:

How many combinations are possible with 10 initial choices and 5 decisions to make if repetition is allowed?

i used

(r + n – 1)!/r!(n – 1)!
(5 + 10 - 1)!/5!(10 - 1)!

To determine the number of combinations that can be made with 10 choices, 5 decisions to make, and no repetition allowed, we can use the formula for combinations.

The formula for combinations is given by:

C(n, r) = n! / (r! * (n - r)!)

Where:
C(n, r) represents the number of combinations
n is the total number of choices
r is the number of decisions or positions to fill
! represents the factorial operation

Using the given information, we have:

n = 10 (10 choices)
r = 5 (5 decisions to make)

Plugging these values into the formula, we can calculate the number of combinations:

C(10, 5) = 10! / (5! * (10 - 5)!)
= 10! / (5! * 5!)

To calculate the factorial, we multiply all the numbers from the given value down to 1.

10! = 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1
5! = 5 * 4 * 3 * 2 * 1

Substituting the factorial values into the equation:

C(10, 5) = 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1 / (5 * 4 * 3 * 2 * 1 * 5 * 4 * 3 * 2 * 1)
= 10 * 9 * 8 * 7 * 6 / (5 * 4 * 3 * 2 * 1)
= 3024 / 120
= 252

Therefore, there are 252 combinations that can be made with 10 choices, 5 decisions to make, and no repetition allowed.