UPSC NDA Math Model Paper 10

Since a 3-digit number cannot start with digit 0,
The hundredth place can have any of the 4 digits.
Now, the tens and units place can have all the 5 digits. T
Therefore, the total possible 3-digit numbers are 4 × 5 × 5, i.e., 100.
The total possible 3 digit numbers having all digits same = 4
Hence, P (3-digit number with same digits) =4/100 = 1/25