Question

The number of four digit odd numbers that can be formed so that no digit being repeated in any number is

• A. $2240$
• B. $2420$
• C. $2440$
• D. $2520$

Answer 1

The correct option is A $2240$

Since we have to find the number of four digit odd numbers, so unit digit must be either $1,3,5,7$ or $9$. Therefore there will be five way to fill the unit place.
Now at Thousand place out of $0,1,2,3,4,5,6,7,8,9$ we can fill it in $8$ ways because one of them is used at unit place and $0$ can't be at thousand place.
So, required solution is $8\times 8\times 7\times 5=2240$