Well it depends on how long after you wait the 8 minutes And there is no table to use if you can give me the table i will help you.
<span>F(x) = (1/4)^x
</span><span>F(3) = (1/4)^3 = 1/64
</span><span>B. 1/64</span>
At time t = 1 hr... fee is initial ($12)+ ($8) = 20<span><span>ribhu </span> 10 months ago</span>and so on... the intercept would be initial fee... which is $12 charged at t=0 hr
thats the best i can do