Question

Find the sum of all the numbers that can be formed with the digits $2,3,4,5$ taken all at a time.

Answer 1

$\overline{{10}^3}$ $\overline{{10}^2}$ $\overline{{10}^1}$ $\overline{{10}^0\downarrow }$

$2,3,4,5$

(image )

Sum$=(2+3+4+5)({10}^0+{10}^1+{10}^2+{10}^3)$

$=15(1+10+100+1000)$

$=1111\left(15\right)$

$=16665$