Question

how many 3 digit numbers can you form by using each of the digit 7,8,1, only once?​

Answer 1

Answer:

781

187

718

817

178

871

Hence 6 three digit number can be formed.

Answer 2

Given:

Digits: 7, 1, 8

To find:

Three-digit numbers using given digits only once

Solution:

The required number of terms is 6.

We can calculate the required number by using the concept of permutation.

We have to use 7, 8, and 1 only one.

So, the total digits=3.

We can form a three-digit number in 3! ways.

So, the number of terms=3!

=3×2×1

=6 terms

These terms are as follows-

781, 718, 871, 817, 178, 187

Thus, the number of terms required is 6.