Question

Number of $4$ digit numbers using digits $0,1,2,3,4,5$ which are divisble by $9$, when each digit used at most once

• A. $30$
• B. $32$
• C. $36$
• D. $40$

Answer 1

The correct option is C $36$

The number will be divisible by $9$ if sum of all the digits are divisible by $9$
Hence possible digits are $(0,2,3,4)$ or $(0,1,3,5)$
So total possible numbers are $=2\times 3\times 3\times 2\times 1=36$