we are asked to determine the probability of getting heads every time if we flip a coin 7 times. To determine this:
If we flip a coin once then there are two possibilities: Head, tails.
If we flip twice we have: (head, tails); (tails, head), (head, head); (tails, tails) there are 4 possibilities
If you flip it 3 times you have 8 possibilities. In general, if you flip the coin "n2 times you get:

possibilities.
Now, there is only one way we can get heads each time. therefore, the probability is:

That equivalent to 0.78% probability.