Question

How many $3$-digit numbers can be formed from the digits $1,2,3,4$ and $5$ assuming that repetition of the digits is not allowed?

Answer 1

A three digit number is to be formed from given $5$ digits $1,2,3,4,5$.

$\square \square \square HTO$

Now, there are $5$ ways to fill ones place.

Since, repetition is not allowed , so tens place can be filled by remaining $4$ digits.

So, tens place can be filled in $4$ ways.

Similarly, to fill hundreds place, we have $3$ digits remaining.

So,hundreds can be filled by $3$ ways.

So, required number of ways in which three digit numbers can be formed from the given digits is $5\times 4\times 3=60$