KEAM 2019 Math Paper

The total number of arrangements of 10 digits 0,1,2,3,4......9 by taking 4 at a time
=‌10C4×4!
In every arrangement of 4 selected digits there is just one arrangement in which digits are in ascending order. Hence, Total=‌

‌10C4×4!

4!

=‌10C4