Question

Compute the number of eleven-digit integers that can be formed using all of seven 1s and four 0s if you never start or end with a 0 and no 0s are ever next to each other.

Answer 1

Start with seven 1's next to each other.
Add four zeroes to the six spaces between the ones.
There are C(6,4) ways to do this.
Hence the same number of 11 digit numbers.

Answer 2

Can you explain the process of finding the answer more I'm a little confused