A battery charge. The percentage of the batteries capacity that is charge as a function of time in minutes as craft. How many percent are at it every six minutes? Is it 12%, 2%, 10% or 6%?

The percent that is added every minute is given by the slope of the line,
The slope of the line is given by:
[tex]\frac{100-40}{30-0}=\frac{60}{30}=2[/tex]Therefore, the percent that is added every minute is 2% per minute.
Therefore, the percent that is added every 6 minute is 12% per minute.