How many [math]9 -bit strings (that is, bit strings of length 9) are there which:

- Start with the sub-string 101? Explain.
- Have weight 5 (i.e., contain exactly five 1’s) and start with the sub-string 101? Explain.
- Either start with [math]
101 or end with [math]11 (or both)? Explain. - Have weight 5 and either start with 101 or end with 11 (or both)? Explain.