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?
How many four-digit numbers can be formed with the digits 3,5,7,8,9 which are greater than 7000, if repetition of digits is not allowed?
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?