How many 3digit Base Twelve numbers are there that contain e

How many 3-digit Base Twelve numbers are there that contain exactly one B? (Note:

the digits for a base twelve number are {0,1,2,3,4,5,6,7,8,9,A,B})

Solution

let B is at first place, then remaining two place can be filled using remaning 11 digits as P(11,2)=11!/9! = 11*10 =110

Now B can be of any three places, so total digits are

3*110 =330