how many bit strings of length 10 either start with 000 or end with 1111??????
Thank you very much
Hello,
Well, keep 000 at the beginning.
Then there are 7 remaining bits that are to be chosen.
Each with two possible values : 0 & 1.
So it's 2^7.
Now, keep 1111 in the end.
There are 6 remaining bits that are to be chosen.
Each with two possible values : 0 & 1.
So it's 2^6.
Total number : 2^7+2^6 (if you have to include the case where it both starts with 000 and ends with 1111)