Before you start charging, the battery is at 1 volt. At this point, the time is 0.

Plugging these values into the equation gives 1 = 12 - A (2^0) = 12 - A.

Therefore, A = 11.

Now that we know A, we can answer b).

At t=6, v = 12 - 11(2^-6) = 11.83V (2 decimal places)

For c), we know v and need to find t.

11.9 = 12 - 11(2^-t)

11(2^-t) = 0.1

2^-t = 0.0090909...

-t = log(2) 0.0090909... = -6.7813...

t = 6.7813... hours.

To convert the remainder into minutes, we multiply by 60.

0.7813... x 60 = 47 minutes, to the nearest minute.

Therefore, the total charging time is 6 hours, 47 minutes.