Probability is what percent of the time something will happen on the average.
Propability could be expressed as a percent of the time, a decimal, or a
fraction of the time.  It's "unit" is always of the time.

The coin is heavier on one side than the other and it lands heads only 35% of
the time and it lands tails the other 65% of the time, on the average.

You will flip a head only 35% of the time.

Then 35% of the times that you flipped a head first, you'll flip a head a
second time.  So that's 35% of 35% of the time.

Answer: 35% of 35% of the time. = (0.35)(0.35) = 0.1225 or only % of the time.

Andwer: 0.1225 of the time, 12.25% of the time or % of the time, or ths of the time.

Edwin