Combinotorics: forming 3-digit numbers from 1-6 if....

[jshaziza]

How many three-digit numbers can you form from the digits 1,2,3,4,5,6 if
a. the digits can be repeated;
b. the digits cannot be repeated.

I am having trouble figuring this out, can someone please help me. thx.

 

[Deleted member 4993]

Re: Combinotorics

How many three-digit numbers can you form from the digits 1,2,3,4,5,6 if
a. the digits can be repeated;
b. the digits cannot be repeated.

I am having trouble figuring this out, can someone please help me. thx.

For all of those consider

How many ways you can write the first digit?

How many ways you can write the second digit?

How many ways you can write the third digit?

All these are independent events - so you multiply those three events.