Question

The number of numbers that can be formed using $1,2,3,4,5$ which are greater than $40000$, if repetition of digits is not allowed is

Answer 1

A five digit number is of form $\_\_\_\_\_$
For the number to be greater than $40000$
First place can be filled by $4$ or $5$, so $2$ ways
Remaining places can be filled in $4!=24$
$\therefore$ The required numbers $=2\times 24=48$