How many four digit different numbers, greater than 5000 can be formed with the digits 1, 2, 5, 9, 0
Question:
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?
Solution:
As the number has to be greater than 5000, the first digit can either be 5 or 9.
Hence, it can be filled only in two ways.
Number of ways for filling the second digit = 4
Number of ways for filling the third digit = 3 (as repetition is not allowed)
Number of ways for filling the fourth digit = 2
Total numbers $=2 \times 4 \times 3 \times 2=48$