SOLUTION: How many 12-bit strings (that is, bit strings of length 12) are there which have weight 7 and either start with 011 or end with 01 (or both)?
Question 1175300: How many 12-bit strings (that is, bit strings of length 12) are there which have weight 7 and either start with 011 or end with 01 (or both)? Answer by ikleyn(52787) (Show Source):