Question

Using the digits $1,2,3,4,5,6$ find the numbers between $3000$ and $4000$ which are divisible by $5$.

Answer 1

The first digit has to be 3

Second digit has 6 choices, similarly third and fourth digit each have 6 choices (If repetition is allowed)

$1\times 6\times 6\times 6=216$

$216$ Numbers can be formed.

if repetition is not allowed

$1\times 5\times 4\times 3=60$

$60$ numbers can be formed.