Question

The sum of all the 4-digit numbers that can be formed using the digits $1,2,3,4$ and $5$ without repetition of the digits is

• A. $399960$
• B. $288860$
• C. $301250$
• D. $420210$

Answer 1

The correct option is A $399960$

R.E.F image

Sum of all four digit number

$=1\left(24\right)({10}^3+{10}^2+{10}^1+{10}^0)+2\left(24\right)({10}^3+{10}^2+{10}^1+{10}^0)+....+5\left(24\right)({10}^3+{10}^2+{10}^1+{10}^0)$

$=24\times 1111\times 15$

$=399960$