The correct answer is A) 3.
We can set up the equation 0.5ˣ = 0.125 to solve this, since we want to know the number of consecutive halves that are taken to get 12.5% (12.5% = 12.5/100 = 0.125).
To solve this, use logarithms:
[tex]\log_{0.5}0.125=x
\\
\\3=x[/tex]