Answer:
Q1 is: 2.2 percent per minute
Q2 is: 35 minutes
Explanation:
For the first question, take 89 percent, and subtract 23 from it, then divide by 30 minutes for the rate per minute.
For the second question take 23 percent, find out how much is left until 100 percent (77 percent) and use the rate from the last question (2.2 percent per minute), to find out how much time charging 77 percent takes. (You get 35 by using: 77 divided by 2.2)