UPSC NDA Math Model Paper 9

For the number to be divisible by 10 at least one '0' should be there at the end
So, only four digits are left to be arranged and last digit is fixed as 0
For 3 digit number, (_ _ 0)
Number of ways of arranging 4 digits on 2 places =4P2=12
For 4 digit number, (_ _ _ 0)
Number of ways of arranging 4 digits on 3 places =4P3=24
Total ways =12+24=36