Question

How many 3-digit positive intergers can be written using the digits 1,2,4,7,8?

Answer 1

Can digits of the i-n-t-e-g-e-r-s be repeated?

Is 111 allowed?

Answer 2

@jocelynna97

Answer 3

I'm sure

Answer 4

How do you even go about solving this problem?

Answer 5

So, 111 is acceptable? I am uncertain what you mean by "sure." @jocelynna97

I have to know is repetitions are allowed before we can start working on the problem?

Re-read the instructions. Numbers like 144 and 101 and 444? Are they allowed? The instructions should make that clear.

Answer 6

The thing is it doesn't its just straight forward but in examples we used in class we were able to use repeated digits so I'm almost certain it's a yes

Answer 7

How many 3-digit positive intergers can be written using the digits 1,2,4,7,8? Allow repetitions.

There are 5 choices for the first digit.
Because repetitions are allowed, there are 5 choices for the second digit.
And, the 5 choices for the third digit.

Answer 8

According to the Counting Principle,
there are 5*5*5 possible 3-digit numbers that can be made from the given 5 digits, allowing for repetition of a given digit.

Answer 9

If repetition of given digits is not allowed, there are 5 choices for the first digit, 4 for the second, and 3 for the third. 5*4*3 total

Answer 10

Okay thank you so much! I think I understand now :)

Answer 11

Glad to help. These counting problems can be confusing.