Knowing that an hour has 60 minutes, add 25 minutes to 9:55 to get 10:20. Another way to think of this is by adding 25 to 55 to the base of 60. Assuming that he only had to mow the front and back yard, add 45 minutes to 10:20 to get your final answer.
The final answer should be: 11:05 am.
