How many four digit different numbers, greater than 5000 can be formed with the digits 1,2,5,9,0 when repetition of digits is not allowed?

Since the required numbers are greater than 5000.
$\therefore$ The thousand's place can be filled with any of two digits 5 or 9.
So, there are 2 ways of filling the thousand's place.
Since repetition of digits is not allowed, so the hundred's ten's and one's places can be filled in 4,3 and 2 ways respectively.
Hence, the required number of numbers
=$2\times 4\times 3\times 2=48$