Permutations and Combinations Part 2

No of 5 digit numbers starting with digit 1
=5×5×5×5=625
No of 5 digit numbers starting with digit 2
=5×5×5×5=625
No of 5 digit numbers starting with 31
=5×5×5=125
No of 5 digit numbers starting with 32
=5×5×5=125
No of 5 digit numbers starting with 33
=5×5×5=125
No of 5 digit numbers starting with 351
=5×5=25
No of 5 digit numbers starting with 352
=5×5=25
No of 5 digit numbers starting with 3531 =5
No of 5 digit numbers starting with 3532 =5
Before 35337 will be 4 numbers,
So rank of 35337 will be 1690
So, in descending order serial number will be
3125−1690+1=1436